Islamic Navigational Knowledge in Ming China 牽星術：明代中國的伊斯蘭導航知識

國立清華大學歷史研究所乙組

碩士論文

Fettering the Stars: Islamic Navigational Knowledge in Ming China 牽星術：明代中國的伊斯蘭導航知識

研究生: 林筱倩 (Hsiao-chien Lin)

學號: 101043513

指導教授: 王憲群 (Hsien-chun Wang)

中華民國一○四年六月

摘要

宋元以來，伊斯蘭世界與中國之間，藉由成熟的海洋技術而有著頻繁貿易的往來，

不同文化之間的交流亦隨之興起。在中國航海史上著名的航海家鄭和（1371‐1433），曾 在十五世紀初期帶領著船隊七次下西洋，航程遠至非洲東岸。歷史材料提及鄭和船隊可能 利用一種名為「牽星術」的導航技術，並使用一種名為「牽星板」的導航儀器。藉由這樣 的儀器，導航員可在夜晚中測量星體和地平線的仰角，並以「指」為測量單位，了解船隻 的位置，以成功達到越洋航行的目的。本論文主旨即在探討這種導航技術與儀器背後的多 文化語言與天文知識的基礎。

我發現在遠洋航行中，水手必須熟練於時間的掌握及方位的辨識，他們藉由觀察星 體的運行來解決這兩個問題。而在印度洋及阿拉伯海之中，使用泰米爾及馬拉姆語的水手 們，便相當善於運用這樣的導航技術。這樣的技術藉由星體仰角的高度來判斷時間，並以 zām 為單位。zām 是一種古代印度計算時間的方式，主要使用特定亮星及月亮做為觀測 同樣為手指的意思。配合 zām 的計時方，(إصبع) 的依據，測量出 「指」，阿拉伯語為 isba 式，得以在汪洋大海中了解航行所花費的時間。水手們更利用在黃昏或清晨時分，藉由亮 星於海平面的位置，來判斷方位。除此之外，在儀器的使用上，類似「牽星板」的航海儀 器有著多種形式的存在。例如，水手在測量的時候，可以使用相同的板子但運用不同的結 點，或者使用不同大小的板子，但繩長不變，亦或是板子大小不同且同時隨結點改變。在 中國史料中，明代李詡《戒庵老人漫筆》等材料顯示，牽星板是一組由十二塊大小不同的 木板組成，顯示華人地區所使用之「牽星板」為板子多塊的類型。而在中國的歷史材料 《武備志》中，除了記載此項航海技術的遺跡，也標示著稱為「針路」的中國傳統航海方 式。此種特殊的繪圖方式，即說明多種文化的導航知識存在於這條航線上。另一方面，我 們亦可從使用方式和儀器的名稱上窺見知識的流動，例如「牽星」一詞在阿拉伯語中為

同為牽引的意思，為一種記憶天體相對位置的特定記憶方法。令人驚喜的，(تكبيل) al‐qaid 是，更多語言關連如同「牽星」和「指」的例子，隨著航海技術的達發而存在於此條航線 中。綜合以上而言，不論從史料或是語言翻譯上，都可以看出跨文化知識傳遞的軌跡。

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最後，我根據《前聞記》的航程記載，逐步說明鄭和越洋航行之時所使用的導航知 識。發現船隊利用季風做為動力，於冬季利用東北季風出發，並順著夏季的西南季風回程。 此外，從《武備志》裡「過洋牽星圖」的記載中，了解船隊主要仰賴現今北極星、昴宿星 團、北河三、南河三、老人星和南十字星，以確認船隻在固定緯度的航線之上。與此同時， 導航員利用「牽星板」等相似儀器，除了確認船隻所處緯度，更測量星體在天空仰角的變 化，搭配 zām 這種計時方式而得知航行時間。

因此，本論文認為，此類航海技術的發展非一蹴可及，鄭和並非第一位於此條航線 上航行之人，鄭和下西洋所使用的導航技術，乃是一個多文化交流之下的成果，包含著伊 斯蘭、印度、與中國等不同文化的導航技術。因此，鄭和的壯舉，其實是多文化交流之下 的結果。

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Abstract

Beginning from the Song and Yuan Dynasties, Muslim and Chinese ships frequently sailed the south China coast, Southeast Asia, Sri Lanka, and the Persian Gulf, trading goods and cultures. The Chinese naval commander Zheng He 鄭和 (Cheng Ho, 1371‐1433) lead seven expeditions along these sea routes, sailing as far as the east coast of Africa in the early 15th century. Historical sources mention that Zheng He used a navigation method called qianxing shu 牽星術, which employed a particular instrument named qianxing ban 牽星板. Navigators could use this instrument to measure the angle between stars and horizon to find units of zhi 指. They used this technique to understand the location of their ships while sailing in the open‐sea. This thesis discusses the linguistic connections between different cultures and the astronomical knowledge behind that technology.

Time and direction were essential to this maritime technology, and this technology united these two issues by observing stars. This technique relied on the altitudes of stars and horizon to define time. Moreover, it used zām, which was a special time‐measurement system in ancient India, as a unit of time and measured the specific bright stars and the moon in terms of in Arabic. Both words mean “finger.” Also, navigators observed (إصبع) zhi 指 in Chinese and isba the bright stars on horizon in dawn and dusk to understand directions. This technique employed the instrument qianxing ban, which can be classified in different types: those with knotted strings and a single board, those with unknotted strings and boards of different sizes, and those with both knotted strings and different sizes of boards.

By the seventeenth century, a treatise on armament technology reported that Chinese sailors carried magnetic‐needle routes marked with gen 更. These maps were typical of traditional Chinese maritime technology, but also contained information about the stars in terms of the unit zhi which was familiar to most sailors in the Indian and Arabic Oceans. Thus, these sea‐charts prove the cultural interactions on this sea‐route.

Finally, Zheng He’s voyage is reconstructed. Zheng He’s fleet exploited the power of the monsoon. They relied on the northeast wind to depart in winter, then followed the southwest iii

wind to return to China in summer. Moreover, Zheng He’s navigators relied on the altitudes of Pole Star, Pleiades, Pollux, Procyon, Canopus and Southern Cross for directions. In this way, sailors could keep on the right route. Meanwhile, they used qianxing ban to measure the angle of stars. They also used the zām time‐measurement system to measure time. In conclusion, the qianxing shu and qianxing ban were the result of centuries of cultural communications between China, India, and the Islamic world.

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Contents

Introduction……………………………………………………1

Navigational Skill and Lunar Mansions………………7

Introduction…………………………………………………………………7

History of Navigation…………………………………………………….8

Chinese Navigation……………………………………………………….9

Arabic Navigation……………………………………………………….14

Isba and Zām…………………………………………………………..….17

Navigation methods…………………………………………………...23

Qiyas………………………………………………………………………………….….23

Fettering…………………………………………………………………………….….25

Abdāl…………………………………………………………………………..…………26 v

Navigational Miscellany………………………………………………..……….27

Monsoon……………………………………………………………………28

Monsoons of the Arabian Sea………………………………………………..28

Monsoons of the Indian Ocean………………………………………………28

Lunar Mansions………………………………………………………….32

Definition of Lunar Mansions……………………………………..32

Simple Astronomy………………………………………………………………….33

Development of Astronomy……………………………………………..…...35

Lunar Mansions in different cultures………………………….45

Astronomy: Mansions mark day of month……………………………..51

Connection of Lunar Mansions to Navigational Astronomy……53

Use of Lunar Mansions in Time‐Keeping…………………………….….54

Conclusions…………………………………………………………….….55

How to Use Lunar Mansions………………………………………………….55

Relationship with Navigation……………………………………………..….56

Instruments………………………………………………..…..60 vi

Introduction………………………………………………………….……60

Compass Rose and Magnetic Compass…………………….…62

A. Magnetic Needle Compass (Chinese)…………………………….…..64

B. Zām compass (India, Arabic)………………………………………….…..68

Astrolabe……………………………………………………………….…..75

History, Greek to Arabic…………………………………………………….…..75

Parts of the Astrolabe…………………………………………………………...76

Uses of Astrolabe…………………………………………………………….…….83

Results, latitude, and time…………………………………………………..…88

About Qianxin ban and Liangtian chi …………………….…..89

The Liangtian chi……………………………………………………..…90

What is the Qianxin ban……………………………………………..94

A. Knots………………………………………………………………………………...95

B. Different sizes………………………………………………………….……..101

C. Different Sized Boards with Knots……………………………..…….101

Conclusion……………………………………………………….……..102 vii

Zheng He……………………………………………………….105

Introduction……………………………………………………….….…105

Background………………………………………………………….…..106

How Did Zheng He Succeed in His Voyage?...... 112

Linguistic Connections………………………………………………125

Development of Instruments……………………………………127

Conclusion……………………………………………………………….131

Conclusion…………………………………………………….135

Reference………………………………………………………141

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Introduction

In the fifteenth century, the Ming Dynasty eunuch admiral Zheng He 鄭和(1371‐1433) commanded seven expeditionary sea voyages to southeast Asia, South Asia, and even eastern Africa. Historians hail the voyages as China’s greatest achievement in overseas exploration. Actually, though, this sea‐route had developed generations before Zheng He’s voyage. For example, Faxian 法顯 (337‐422) had traveled in search of classical books on Buddhism. In Faxian’s account, he described the sea route by reporting locations and the number of days of travel between them. The sea‐route he described streched from Sri Lanka to the strait of Malacca and back to Guanzhou 廣州. 1 This last location, Guanzhou, was an important harbor which had been developed in Southern Song Dynasty by foreign merchants.2 As the account by Faxian illustrates, this sea route had been traveled for several generations before the Ming Dynasty. Nevertheless, historians are unable to explain how, in terms of navigation, admiral Zheng and his mariners managed to sail across the Bay of Bengal or the Arabian Sea. They often mention a technique called “star‐fettering” (qianxing 牽星) but cannot agree how it worked. Clearly, this star‐fettering technique demands further research and, given the Western destinations of Zheng He, a possible coordination with Islamic origins. Until the Ming Dynasty, the great Zheng He expedition represented the high point of maritime technology. However, because such voyages had been possible for several generations, it is more interesting to ask what kind of conditions could produce these voyages. Ming Dynasty mariners might have used the stars as a guide. According to a twelfth century record of China’s maritime trade, the Phingzhou Table‐Talk (Pingzhou Ketan 萍洲可談, 1191), mariners certainly used the stars as a guide: “Navigators know geography. [They] observe the stars at night and the sun in the daytime, and [they] use the compass on cloudy days. (夜則觀星，晝則觀日，陰晦

1 Ding, Qian 丁謙, 1971, p.10B‐11A. 2 Kuwahara, Jitsuzo 桑原騭藏, 1971, p.30. ‐ 1 ‐

則觀指南針).” 3 Unfortunately, this passage does not provide any practical information about how the stars could be used as a guide and whether any instruments were involved. Slightly more information, especially about Zheng He’s voyages, can be found in a seventeenth century military treatise, Treatise on Armament Technology (Wubei zhi 武備志, 1621). This book contains a set of schematic charts showing Zheng’s routes from Nanjing, the administrative stronghold in east China, to Qeshm Island in the Strait of Hormuz. The term zhi (finger 指) appears next to the dotted lines after certain digits, indicating that it is a navigational unit.4 (Figure 1) The treatise also includes a set of four diagrams entitled “the Chart of Sea‐ Crossing by Fettering Stars (Guoyang qianxin tu 過洋牽星圖, 1621), which show how constellations could have guided Zheng He’s fleet from Sumatra to Sri Lanka and Calicut to Hormuz.5 (Figures 48 and 50) The terms zhi (finger) and qianxing (star‐fettering) are intriguing. A sixteenth century notebook (biji), Casual Notes of the Old Man of the Discipline Monastery in Elite Theater (Jie’an laoren manbi 戒庵老人漫筆 1597) by Li Xu 李詡 (1506‐1593), includes a passage entitled zhoubi suanchi 周髀算尺. It is not clear what the zhoubi suanchi is or whether it has anything to do with the ancient mathematical treatise The Arithmetical Classic of the Gnomon and the Circular Paths of Heaven (Zhoubi suanjing 周髀算經, about First century B.C.). One more sixteenth century source shows that the term zhi relates to navigation. Record of the Tributary Countries of Western Oceans (Xiyang chaogong dianlu 西洋朝貢典錄, 1520), a book which records Ming China’s communication with foreign countries, vaguely suggests that, in order to sail to the Kingdom of Liushan (溜山國), now the Maldives, one has to sail according to the Pole Star and take a certain number of digits of zhi as the reference point in their voyage.6 However, the text does not tell us exactly how the technique worked. The available Chinese sources also seem to suggest that at least by the fifteenth century Ming Chinese navigators used a kind of navigational tool, called “star‐fettering boards” (Qianxin

3 Zhu, Yu 朱彧 1191, p.1644. 4 The charts are named “Zheng He’s Sea‐Chart from Nanjing to Foreign Countries” (Zi Baochuan Chang Kaichuan Chang Cong Longjiang Guan Chu Shui Zhida Waiguo Zhufan Tu 自寶船廠開船從龍江關出水直抵外國諸番圖). 5 Mao, Yuanyi 茅元儀 1621 , p.319. 6 Huang, Shengzeng 黃省曾, 1520, unpaginated. ‐ 2 ‐

Ban, 牽星板) to measure the angle between the horizon and certain constellations in units of zhi and jiao. Historians of Chinese science argue that both the star‐fettering technique and the boards might have an Islamic origin.7 In his examination of the Wubei Zhi, George Phillips pointed out that the technique of using zhi to measure the angle between the horizon and the stars was also used by the Moorish pilot engaged by Vasco de Gama in the early sixteenth century.8 Yen Dunjie 嚴敦杰 argueed that the star‐fettering technique originated from the Islamic world and that one zhi equals to 1 36/60 degrees.9 Joseph Needham suggested that fifteenth‐century Portuguese sailors, who were under Islamic influence, might have used a similar technique. He also noted that the Islamic instrument, named the kamal, was similar to the star‐fettering boards.10 However, some Chinese historians have argued that the boards evolved out of an ancient Chinese instrument named the “heaven measuring ruler” (liangtian chi 量天尺).11 This argument about the Heaven Measuring Ruler is implausible. Different kinds of astronomical instruments, mainly sundials, have been named Heaven Measuring Rulers but have nothing to do with navigation. Although it is possible that a certain kind of Heaven Measuring Ruler was used as a navigational tool, there is no evidence showing how it functioned. Thus, since the sources had connections with Western culture, these sources should be related to other civilizations which were on this sea‐route. Firstly, modern scholars have studied the communication between the Islamic world and China. For example, Su Liangbi 蘇良弼12 mentioned that from the beginning of the Song Dynasty, there were mosques in Quanzhou, the most important port for those doing business with the Islamic countries. The cultural exchange started well before the Song Dynasty. It is known that Ibn Wahab el‐Basri met the Chinese emperor in A.D. 876. El‐Basri travelled from the Red Sea and the Persian Gulf to do business in

7 Yan, Dunjie 嚴敦杰, 1966, p.77‐88. 8 Phillips, George, 1898, p.219‐220. 9 Yan, Dunjie 嚴敦杰, 1966, p.77‐88. 10 Needham, Joseph, 1954, p.574. 11 Wang, Lixin 1983, p.122‐189; Hangyun Shihua Bianji Xiaozu 航運史話編輯小組, 1978, p.170‐189. 12 Su, Liang Bi 蘇良弼, 1988, p.81. ‐ 3 ‐

China. Similarly, Yang Waizhong 楊懷中13 has stated that from the eighth to fifteenth centuries, Arabian sailors had trading businesses across the ocean, and that Chinese Muslims were experts in navigation starting from the Yuan Dynasty. Wei Dexin 魏德新14 has discussed some Chinese Muslims who traveled together with Zheng He. One of them, named Wang Jingheng 王景弘, was a Chinese Muslim and an expert sailor of the Ming Dynasty. In addition, Ma Huan 馬歡 recorded the landscape, the local environment, and culture in his book Yiya Shenglan(瀛涯勝覽, 1451) . Fei Xin 費信 (1388‐?), who collected local information and preserved the descriptions of different countries in the book Xengcha Shenglan (星槎勝覽, 1436), also travelled with Zheng He. All of these writers were Muslims. In addition to Chinese travelling to Arabia, Muslims gained greater influence in China than they had before. The most visible figure of Arabian descendant was named Pu Shougen 蒲壽庚 (1245‐1284). He managed foreign ships and businesses in Quanzhou from 1250 to about 1275. The Pu surname was a strong clan in Quan Zhou. They were a famous Chinese Muslim family and were experts at interacting with Muslim merchants. Wei Dexin argues that Pu Rihe 蒲 日和, Pu Shougen’s nephew, also travelled with Zheng He and played an important role in his voyages. Zheng He was also born into a Muslim family. The emperor ordered Zheng He to relocate to Quanzhou. Chen Guoqiang 陳國強 shows that because he was a Muslim, Zheng went regularly to mosques to pray. From Quanzhou, he traveled to the Western Regions with Pu Rihe and other Muslims of Quanzhou. Apparently, Zheng had strong connections with Islamic culture and most likely was familiar with the Islamic technology, especially as far as navigation instruments are concerned. 15 Zheng He’s Islamic background could have played an important role in obtaining navigational knowledge. According to the historian of Islamic culture Paul Lunde, the famous sailor Ahmad Ibn Mājid used the Pole Star to determine the latitude. Ibn Mājid could measure its height above the horizon and relate that height to latitude. Keeping the Pole Star at the same

13 Yang, Waizhong 楊懷中 2005, p.191. 14 Wei, Dexin 魏德新 2005, p.233. 15 Chun, Guoqing 陳國強 1988, p.126. ‐ 4 ‐

height would be equivalent to sailing from east to west or back on same latitude. Ibn Mājid also mentioned that to measure of the Pole Star’s height above the horizon, sailors used something

Portuguese sailors had found latitude by measuring the altitude of the .( كمال) ”called the “kamal sun. This method was influenced by Arabian sailors of the thirteenth century. Sailors determined their latitude according to Pole Star, thus to find their longtitude and time, they had to rely on the zām system and lunar mansions. The argument that Chinese navigators had Islamic connections holds promise. As George means finger in Arabic, and one isba is equal to eight zām.16 The (إصبع) Phillips has noticed, isba terminology is similar to the Chinese system mentioned above. Moreover, G. R. Tibbett has .(تكبيل) pointed out that one of the Arabic navigational skills was called “fettering” – al‐qaid Thanks to Tibbett’s commentary and translation of fifteenth century Arabic manuscripts of navigation, the evidence is clear that Arab sailors measured the distance between the star Aries and Dibban as four isba, or four times the width of a finger. They also used similar methods to measure the distance between the stars and the horizon to maintain their courses. When sailing along the coastlines, sailors additionally used tides, winds, landmarks, coral, plants, or the types of marine creatures indigenous to the area, as markers of their positions. More importantly, observing monsoons and ocean currents as well as the positions of the stars and the lunar mansions would have been crucial for timekeeping and maintaining courses.17 Therefore, to understand how Zheng He and his fellow mariners used the star‐fettering system and the lunar mansions to sail across the Bay of Bengal and the Arabian Sea, the Islamic origins of the star‐fettering system must be considered and the astronomical knowledge behind it must be examined. After such a reconsideration of the evidence, an attempt may be made to combine Chinese and other civilization sources. Chapter One will discuss the historical background of China’s communication with the Islamic world by the fifteenth century. Chapter Two will explain the art of navigation and the meaning of the isba and zām. In addition, this chapter will explore how Chinese and Arab sailors might have used the lunar mansions as a means of time‐keeping. Chapter Three examines how

16 Phillips, George 1898, p.219‐220. 17 Tibbetts, G. R. 1981, p.284‐285. ‐ 5 ‐

the instruments such as the compass, the astrolabe, and the quadrant were used in navigation. Chapter Four tries to explain the navigation of Zheng He’s voyage by simple steps. Moreover, this chapter presents the different works on navigational knowledge in different cultures along this sea‐route. Chapter Five presents some conclusions and directions for future research.

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Navigational Skill and Lunar Mansions

Introduction Navigation has a long history. The Greeks and Romans reported stories about their achievements in navigation. For example, Herodotus wrote that the Persian king Darius (550‐ 486 BC) sent a ship to discover a sea‐route to Arabia and the Persian Gulf.18 To make this discovery, King Darius asked a Greek sailor named Scylax to find the route from India to Egypt. Two centuries after Scylax, Alexander the Great asked Nearchus, his navarch or admiral, to reexplore the same route when he returned the triumphant Alexander from the Indus River in Pakistan to the port city of Susa in the Persian Gulf. Through the Ptolemaic Era, Egyptian traders used this familiar route and established Socotra, an island of near the Horn of Africa, as a trading‐post on the path between Egypt and India. Clearly, Europeans had been trying to reach eastern destinations for many years. However, unlike their Asian counterparts, a written record of their navigational techniques has survived. Each culture has its own method to navigate, and each culture has its own specific method for sailing. No matter what the method was used in each different culture, the identification of directions was one of the most important techniques. Moreover, the measurement of time is also a necessary technique for navigation, especially for crossing the open ocean. Due to having to measure how long had been sailing, sailors used their particular method to solve this problem. For example, in the Indian Ocean, they measured the movement of stars to understand the passage of time. These methods of telling time can be traced for long time to show how notions of time developed in different cultures. The notion of measuring of time also included the methods and units of counting time. For instance, Chinese used double‐hour, on .(زام) the other side of the water, Indians and Arabs used zām The zām is a special and unique method to measure time by the movement of stars. This method relies on the observation of experiences from several generations. Ancient astronomers observed sun and moon’s orbit. They found the paths and times of their circles and understood

18 Herodotus, Histories, 4.44. ‐ 7 ‐

time passing. For navigation, sailors did not have to be as precise as astronomers who made calendars. However, the sailors used the observation of stars as a reliable method to understand time. Since these bright stars and constellations have strong connections with time‐measurement, some maritime technology developed for methods of guiding boats by stars. At least three methods, the fettering of stars, the qiyas, and the abdāl, comprised the maritime technology for guiding by stars. These technologies were all popular in Indian Ocean and several civilizations were connected in communication by their travels in the Indian Ocean. Therefore, returning to Zheng He’s famous voyage, the fleet departed from Nanjing 南京 and followed the coastline until Southeast Asia, crossed the Indian Ocean and arrived in the Persian Gulf. In this way, they encounted several cultures on this famous sea‐route. Thus, the different maritime technology of Chinese and Islamic cultures must be considered. Because time‐keeping is an important part of maritime technology, the different methods of time‐ measurement and the use of the lunar mansions must be explained. History of Navigation Greeks used stars (and winds) to describe their bearings from the Homeric era until Roman times.19 Other early accounts consider the rising times of the stars and coordinated them with latitude. The early sources on navigation report that the first person to find the direct path to India was Hippalus. Pliny the Elder explained the report by clarifying that Hippalus discovered the uses of the monsoon wind and named it the “Etesian wind.”20 By this account, Hippalus was the first to understand the cycle of the winds and use them to return. Obviously, this story occurred before Arabs developed their sciences of navigation. Although first‐century European accounts describe Hippalus as the discoverer, when Arya Sura wrote the Indian Jatakamala, contemporaneous with the Periplus in first century A.D., he described the arts of pilots and navigators. Arya Sura described the early navigational skills that used bright stars but he also descibed the Bodhisattva as a pilot. Accordingly the High‐minded One possessed every quality required in such a one. Knowing the course of the celestial luminaries, he was never at a loss with respect to the regions of

19 Homer, Iliad,2.145, 9.5, 11.306; Homer, Odyssey, 5.295. 20 Pliny the Elder, Natural History, 6.23‐.26. ‐ 8 ‐

the sky; being perfectly acquainted with the different prognostics, the permanent, the occasional, and the miraculous ones, he was skilled in the establishment of a given time as proper or improper; by means of manifold marks, observing the fishes, the colour of the water, the species of the ground, birds, rocks, and so on, he knew how to ascertain rightly the part of the sea; further he was vigilant, not subject to drowsiness and sleep, capable of enduring the fatigue of cold, heat, rain, and the like, careful and patient. 21 This description is a clue that religion, like trade, could also have an important connection with navigation.

Chinese Navigation This thesis does not focus on Chinese navigation, but it is must say a few words about it. Navigation is only as precise as the needs of the traveller. For example, a map from a 1621 military treatise Wubei zhi 武備誌 presents the itinerary of Zheng He without providing longitude and latitude. Most of the information shown in this map is just mountains and rivers. In addition, the zhenlu 針路 (compass‐needle route), or the distance measured using the twelve traditional watches, or “double hours,” is also an important part of the information presented here. If this kind of map was used, the ships must have sailed along with the coastline. However, because Zheng He used navigational tools in his voyages, he must have used different kind of maps and navigational skills. For regular human activity, it was safer to follow the coastline and the groups of islands and sail there than enter the open ocean. Moreover, there was no reason to doubt this navigational knowledge which had been accumulated from sailors by generations. Zhenglu is a kind of navigation method developed especially by ancient Chinese. This maritime technology arose along with the development of the needle compass. According to the magnetized needle made of lodestone which was placed above the compass rose, sailors not only realized directions, but also rely on the record of maps to understand the sea road. For example, the marks on the Treatise on Armament Technology (Wubei zhi 武備志,1621) recorded readings of the compass needle with a dotted line and told sailors the waterway and directions.

21 Arya Sura, Jatakamala, 14, translated by J S Speyer (first published 1895) ‐ 9 ‐

Figure 1: Selection from Treatise on Armament Technology (Wubei zhi 武備志,1621). The red oval contains the text “滿剌加開船用辰巽針五更.” (Using the chenxun needle to sail from Malaca.)

In addition, these vestiges of the zhenlu can be found not only on the sea charts, but sailors also wrote them down and made something like a guide book for navigation. Versions of these books were called the Book of Zhenlu (Zhenlu Bu 針路簿,) or Book of Genglu (Genglu Bu 更路 簿). These old books collect and record maritime experiences from sailor’s lifetime. They could even accumulate experiences from several generations of the same sailing family. Navigation by the compass needle methods can be traced from Yuan Dynasty in The Customs of Cambodia (Zhenla fengtu ji 真臘風土記, 1312.) The Zhenla 真臘 in this title is the ancient name of Cambodia. According to this record, some water paths were indicated by readings of the compass needle: 又自占城順風可半月到真蒲，乃其境也；又自真蒲行坤申針，過崑崙洋入港…22

22 Zhou Daguan 周達觀, 1966, p.1A ‐ 10 ‐

Sailing with the wind from Champa can take half a month to arrive at Myanmar, and this is just at its border. And going from Myanmar the compass need reads kun shen (roughly, southwest) via Kuanluan Ocean into the harbor. The usefulness of the method led to its popularity and it was still used in the Ming Dynasty. 福州五虎門開船，用乙辰針取官塘，船行三礁東西邊。用丙午針，取東沙山。23 Sailing out of Fuzhou (the capital of Fujian province), Wu Humen, use yichen (roughly southeast) for the compass needle toward Guantang, with the boat passing three reefs on the east and west side. Use biengwu (roughly south‐by‐southest) for the compass needle toward the Dongsha mountain. Sources such as these can still be found nowadays. The Book of Zhenlu, was incorporated into the “Maritime Guide” (Hanghai Zhinana, 航海指南, 1965). This book was compiled by Quanzhou Maritime Museum and preserves the accounts from local sailors. This book contained maritime technology such as tides, winds, and the situation of water flow in different seasons. Moreover, it included lots of terminology used by the sailors. One of these technical terms is zhen 針 which means the direction of the compass needle. In addition, this book describes the shape of mountains or islands which would be seen by sailors as they navigated.

23 Chen, Jiarong, Zhu, Jianqiu 陳佳榮、朱鑒秋, 2013, p.69. ‐ 11 ‐

Figure 2: Image from the Hanghai Zhinana. A description of Mount Tai‐dun and surrounding locations. Sailors recorded descriptions of the landscape such as these to identify their location.

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Figure 3: Selection from the Hanghai Zhinana, unpublished. This figure was taken from a copy preserved at the Quanzhou Maritime Museum. This page describes the magnetic‐needle route of navigation along the coast line. It describes the return from Xiamen to Hainan Island in the South China Sea, and another route from Taiwan to Penghu Island. It records the navigational information, including the jiayin zhen 甲寅針 and chouwei zhen 丑未針. These notes represent the details of the Chinese magnetic‐needle navigation method.

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Arabic Navigation The geographic knowledge used by navigations was no fossilized cultural import. Arabs used Ptolemy’s geocentric astronomy to compute the positions on the earth. The degrees of longitude (distance along a north‐south line) which separated two cities could be determined by the height of the Pole Star. The degrees of latitude (distance along an east‐west line) could be found by differences in the observed times of eclipses. Because Arabic astronomers predicted the sun’s position and calculated eclipses by the techniques described in Ptolemy, they could enlarge and update his Geography with their travels. This information was useful for religious reasons: From ninth to fourteenth century, Arabic astronomers worked to calculate the qibla, which is the direction of Mecca from a given locality. The final result of these investigations greatly improved trigonometric knowledge. Not only did the requirements for prayer determine the Muslim conceptions of geography, the requirement that prayers be offered at certain times created the Muslim conception of time. or ritual prayers The ,(صالة) According to the Koran, observant Muslims needed to offer ṣalāh times of these prayers were astronomically determined. These times are just after sunset ,العشاء) maghrib) when the day begins, according to the Muslim calendar, around nightfall ,المغرب) ,(zuhr ,الظھر) fajr), just after midday or noon ,الفجر) isha) when the stars can first be seen, at dawn asr). Thus, observant Muslims who prayed regularly also became ,العصر) and in the afternoon well‐practiced in astronomical timekeeping, including both calendrical measurements and the observation of hours by day and night. Because prayers were a public practice, the Muslim conceptions of time and space extended beyond the limited circles of astronomy. Moreover, Muslim astronomers knew how to determine latitude and longitude from observations of the azimuth24. As Arabs converted and standardized an increasingly large empire, they adopied the intellectual traditions of the people they encountered. Thus, Arabic astronomy was influenced by Indian philosophy, such as the Siddhantas of Aryabhata and Brahmagupta, from the eighth century. Indian astronomy had been translated into Pahlavi in

24 An arc of the horizon is measured between a fixed point and the vertical circle passing through the center of an object. In astronomy and navigation, this arc is usually measured clockwise from the zero at north through 360 degrees. ‐ 14 ‐

order to write the Zij‐i Shah, or the Astronomical Table of the King, which was produced in the ninth century. In short, Arabic astronomers played an important role by absorbing Indian knowledge and western techniques. As a result, they developed good astronomy and navigation. Some portion of this knowledge travelled with the merchants who probably relied on the same route that Faxian took. Thus, thanks to Tibbetts, the description of navigation by the famous Arabic sailor named Ibn Mājid (1421‐?) has been translated.25 In his introduction to this translation, Tibbetts summarized navigation on the Indian Ocean before the time of Ibn Mājid. Ibn Mājid identifies fā ida͗ ) and gives a chapter to each of them in this book. By Ibn فائدة) ”twelve “useful things Mājid’s style of composition, the “useful things” are lessons on navigation, rather than tools or elements of navigation: 1. How to use compass points and lunar mansions. In this part of his book, Ibn Mājid mentioned In modern Chinese studies, zām is mentioned several times, however, no .(زام) rhumbs and zām one explains clearly what the zām is. In the first chapter, Ibn Mājid explained it is unit for distance. 2. A summary of the basic principles of the sea. Ibn Mājid includes lunar mansions, rhumbs, route distances, latitude measuring, signs of land, the seasons of the sea, the instruments of ship among the second chapter. 3. Lunar mansions. Here, Ibn Mājid focused on explaining the lunar mansions. A lunar mansion is a part of the ecliptic, through which the moon orbits around the earth. Ibn Mājid explains the names and locations of all twenty eight constellations, tells after how many days each mansion rises and sets, and names the bright star in each mansion. Knowing the days on which each star rises into the sky is an important technology for sailors to avoid getting lost. 4. Compass rhumbs. There are nine compass rhumbs which Ibn Mājid names from north to south but he identifies number three pair, al‐Naʿsh and Suhail, as especially good. In his discussion of these rhumbs, Ibn Mājid makes mention of the iṣbaʿ and concludes that this is the best way to measure latitudes throughout the whole of the Indian and Arabian coasts. Ibn Mājid also used the “fettering” to figure out the directions for setting out for lands in Sind, Bengal,

25 Tibbetts, G. R. 1981 p.68. ‐ 15 ‐

China and Red Sea. Here, “fettering” means to tie, or prevent from moving. The Chinese word qian 牽 also has this meaning. Moreover, as Ibn Mājid described, this method of fettering is very similar to the method used to sail in the Arabian Sea. For every iṣbaʿ of increase in the height of the pole star, sailors shoud know the change in latitude. 5. Ibn Mājid gathers several topics into a chapter: stars used as extra rhumbs, other works on astronomy and geography, the Roman months, and the planets. In this chapter, Ibn Mājid mention the planets as days of the week and discusses the planets, but does not relate them directly to navigation. 6.Three sorts of sea route. Ibn Mājid names three types of sea routes. The first one is the route The second one developed from .(ديرة مول,along the mainland, the path of trade (dῑrat al‐mul by which the (ديرة مطلق ,the dῑrat al‐mul and was called the absolute path of (dῑrat al‐maṭlaq ships enter or leave by using measurements. The third path is the path of necessity (dῑrat al‐ which is based on calculations from familiar places. In this case, the ships set ( ديرة اقتضى ͗, iqtidā out from a geographically known place and travel toward a geographically know place. 7. The Maldives and South‐East Asia. In this chapter, Ibn Mājid describes measurements according to the Little Bear, the constellation Ursa Minor. He explains the latitude of Ceylon by measurements of the pole star. Moreover, he introduces latitude measurements from the Red Sea and discusses common failures in taking latitudes. 8. Oceanic environments. Ibn Mājid describes typhoons, other occurrences at sea, seaweed, birds, and how to use these environments on a voyage. 9. Description of the coasts of the world, and measurement of the earth. 10. A geography of places like the Arabian Peninsula, Madagascar, Sumatra, Java, Ceylon, and Zanzibar. 11.Seasons. Ibn Mājid reports the seasons which are suitable for beginning a voyage and for the return. 12. Sea routes, unclear areas, and dangers. Other information on the navigation theory in the fifteenth century Islamic world comes from other sources. In Alfred Clark’s paper “Medieval Arab Navigation on the India Ocean: Latitude Determinations,” he classified four ways that Arabs checked their latitude in Medieval ‐ 16 ‐

times. The first way was to use the pole star. The latitude can be determined from the angle between the Pole Star and horizon. The second method was called a “single star on the meridian.” The meridian makes an imaginary line from north to south. The Pole Star or other bright stars will stand along on this line. This meridian line can be used as a standard to check the distance from other constellations. From these measurements, the latitude can be known. ,By this way, the measurer must chose two stars .(ابدال ,The third way is “substitutes”, (abdāl equally symmetric in altitude along the meridian. Finally, the last way of determining latitude is Obviously, according to experience, the measurer of the latitude could .(قيد ,fettering” (al‐qaid“ follow the bright star to find another bright star. Because the location of these two stars on celestial sphere is known, the measurement can be related to the latitude. This way of knowing latitude is more complicated, but it can be useful because it can be used even when the pole star can’t be measured because of clouds. Ancient Arabic navigational techniques show a rich knowledge of navigation. A deep understanding of these techniques seems to be a necessary condition for navigating by stars. Hence, in the paragraphs below, the units of measure for navigation in the Indian Ocean, and relate these units to a set of simple skills for navigating by the stars.

Isba and Zām a loanword from , ِا ْل ِت َواء) In Arabic, an arc measured in the sky could be called either tirfa Latin curva, curve) or isba. A navigator measured the angle between the Pole Star (or a bright star, or pair of bright stars, as Clark described) and the horizon at a given time. In Arabic, the word isba means “finger.” When used in a navigational sense, an isba is a unit of measure for an arc on the surface of the celestial sphere. Although this name of this unit may have originated from the practice of navigators measuring with their hands, the value of the unit represents almost exactly on modern degree. Moreover, because the arc represents the unit of the angle between horizon and Pole Star, it also represents a unit of latitude. These units were the basic measurements for the navigators, but they also subdivided them. Some studies explained that measurement of the degree, one isba is also equal to eight zām. For example, George Phillips

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has suggested that in Arabic isba means finger and one isba is equal to eight zām.26 In addition, Tibbetts reported that Arab sailors measured the distance between the star Aries and Dibban as four isba, which means four times the width of a finger.27 Today, scholars debate exactly how many of these units equal corresponded to a modern degree.28 Yen Dunjie has inspected the markings on instruments to find that 1 isba equals 1° 36´. They have consulted the seventeenth century military treatise, Treatise on Armament Technology and Chart of Sea‐Crossing by Fettering Stars to determine the magnitude of the isba. This sea‐chart preserves some contemporary notations, such as “華蓋五 指”(Cassiopeia, five fingers), “北辰星一指平水” (Pole Star, one finger above horizon). Whatever the value of the isba, this map uses the isba first to record angles, but also to record the height of the Pole Star at different locations. When Yen Dunjie reconsidered these sources, he argued that the zhi equals to 1° 36´, or 1° + 36/60 °, and originated from the Islamic world.29 He studied the term isba in several contexts and used the celestial coordinate system to reconstruct its value. Yen also explained how he figured out the value for this measurement. At some known latitude confirmed by the altitude of the Pole Star, one isba is very close to 1° 36’ and one zām is almost equal to 0° 12’.30 In another reconsideration of ancient sources, Zhao Lujun 趙鹿軍 tried to calculate the magnitude of the isba by examining thirty‐eight locations marked in the sea‐chart preserved in the Treatise on Armament Technology. From these measurements, Zhao arrived at each isba having a value of two degrees.31 In contrast to this conclusion, José Manuel Malhão Pereira drew on experiences on real naval voyages and arrived at a result of an isba being equal to 1°37’ degree.32 One explanation of these differences may lie in the fact that a word can have two meanings. Although isba is a technical term, it need not have the same magnitude among all

26 Phillips, George 1898, p. 219‐220. 27 Tibbetts , G. R., 1981, p.316. 28 Yan, Dunjie 嚴敦杰, 1966, p. 77‐88. 29 Yan, Dunjie 嚴敦杰, 1966, p. 77‐88. 30 Yan, Dunjie 嚴敦杰, 1966, p. 77‐88. 31 Zhao, Lujun 趙鹿軍；Yan, Xi 楊熺, 1985, p.116. 32 José, Manuel Malhão Pereira, 2003, p.27. ‐ 18 ‐

authors. Different values for a unit of measure are a minor difficulty compared to the different uses of its fractional unit, the zām. One of the meanings of zām is the part of the circle or sphere, specificaly one eighth of an isba. These zām were the “octaval minutes” used by navigators. Another meaning, though, is one eighth of a day. From this meaning, zām came to mean the distance sailed during a zām. For this reason, sailing for south or north will reduce or increase the number of isba in the measurement of the Pole Star, so the distance which the ship has sailed can be related to changes in the measurement of the Pole Star. Given that the earth’s circumference is about 40,075 kilometer and that a ship sails fast enough to raise the Pole Star by 1 isba each day, how far does a ship sail in 1 zām? Let the circumference of the earth be measured as 360°. Thus, 1° is about 111.3 kilometer. Yen Dunjie reports that 1 isba is equal to 1° 36´, (or 1 + 36/60 °). The equation may be written 1 isba  1° 36´ 1 isba  1° + 36/60° 1 isba  60/60° + 36/60° 1 isba  96/60° 60 isba  96° 60/96 isba  96/96° 5/8 isba  1° 0.625 isba  1° 0.625 isba  111.3 km 1 isba  111.3 km / 0.625 1 isba  178.08 km But, from the relationship of time measurments, 1 isba is equal to 8 zām which is again equal to 24 hours.If a ship sails north or south for one day, it raises or lowers the Pole Star by 1 isba.33 If a ship can move the Pole Star 1 isba in 24 hours, how fast is the ship moving? Speed = Distance / Time 178. 08 km / 24 hours 7.42 km / hour Since 1 zām equals 3 hours, a ship that travels fast enough to raise the Pole Star one isba in one day travels roughly 22.26 km over the surface of the ocean in 1 zām. This value agrees very well with the approximation that a zām is 20 km, an explanation of zām commonly found in

33Tibbetts, G. R. 1981, p.297. ‐ 19 ‐

navigational accounts.34According to this explanation, ship sailing a distance of one isba needs to sail for a time of eight zām, or in other words, for one day. Zām not only can be converted into isba but also mean a division of time in Sanskrit. Here one zām is equal three hours. This measurement of time was used in ancient India.35 The Indian sailors dialects also has several terms such as wam, bam, tan, bagan, and maaru. Some of these words seem to be phonetically related to zām. In these uses, one zām indicated a time equal to three modern hours. In the case of sailing, though, the terms which relate to sailing on the open‐sea measure time and distances relative to each other.36 On the other hand, the tirfa method demonstrates what the same words actually meant in Arabic. Tirfa measurements were calculated in zām which had long been used in the Indian Ocean37 as a measurement of distance sailing. There were eight zām in each day in ancient India. They separated the twenty‐four hours into eight parts. Each day time and night time has four zām. It was measured in royal courts also called yamam in Tamil.38In this usage, the zām was the distance travelled by a ship on a fixed bearing in order to raise its latitude by 1 isba.39 That is, the zām means a period of time for how long the ship had been sailing. For this reason, if a navigator sails north and measures the Pole star until it rises by one isba, the time taken was equal take eight zām (twenty‐four hours). The circumference of Earth is large, though. That is why even though the isba is not a large division of the instrument, it still indicates the measurement of an arc. This arc, in turn, can be converted into zām, which is connected with ideas of time‐measurement.

34 Arunachalam, B. 2008, p.202. 35Arunachalam, B. 2008, p.202. 36 Arunachalam, B. 2008, p.202. 37Tibbetts, G.R. 1981, p.299. 38 Arunachalam, B. 2002, p.14. 39 Tibbetts, G.R. 1981, p.299. ‐ 20 ‐

Figure 4: Diagram which shows the relationship between one isba and 8 zām.

So, how did the zām work with navigation? Ibn Mājid gave examples. Suppose there are two ships sailing to the northwest. Both ships see the Pole Star to the north by northwest. Both ships “raise” the Pole Star by one isba, but one ship sails 14 zām and the another sails 16 zām. Ibn Mājid describes how to find which directions the ships sailed. As Tibbetts elaborates, in which Ibn Mājid did not explain for zām clearly for navigation. The basic mistake is the example, there are also two ships, one sailing to the northwest, another sailing to the north–by‐ northwest. After the Pole Star rise one isba, the first north‐bound ship has travelled eight zām and north‐by‐northwest‐bound ship has travelled 10 zām. However, we can not assume that the sum of the two short sides of a triangle minimally equals the longest side.

10 zām 8 zām

2 zām

Figure 5: Diagram which relates one possible arrangement of the zām in a triangle. The dimensions of the triangle may vary by wind.

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Actually, when these details are combined with zām and other directions, it can be found that the hypotenuse of triangle is actually described by the directions on the compass. The figure below shows the Arabic compass, with the number of zām added to the directions. These zām indicate how long a ship would have to sail in each of these directions in order to reach the same distance to the north. These numbers of zām were from Sulaimān who was another famous navigator and lived later than Ibn Mājid. Very possibly he could have relied on Ibn Mājid’s idea and used them to navigate the Arabian Sea and the Persian Gulf.40 Thus, since these numbers are a little different, it could be very possible that the different sailors had different ideas according to their personal or experiences from their navigational familiar. After all, technical navigational knowledge was transmitted between cultures and accumulated from several generations.

Figure 6: An Arabic compass‐rose. The arrows in the middle of the compass are very similar to the “wind roses” marked on sea‐charts. As Tibbetts described, directions were also named by zām, and the names actually contained elements of spherical trigonometry which could be used with stars to tell navigators how long to sail in each direction. ( G.R. Tibbetts, 1981, Arabic Navigation In The Indian Ocean Before The Coming Of The Protuguese, London, Royal Asiatic society books, p.297.)

40 Tibbetts, G.R. 1981, p.302. ‐ 22 ‐

Navigation methods

Qiyas Qiyas can be assumed to be general navigation methods. The most famous and important of the qiyas is the technique of using the Pole Star. The Pole Star is like the axis of heaven and all stars move around this. As we have seen, sailors measured the Pole Star, or when they were close to the equator, they at least measured the nearby stars. The Pole Star will change its altitude from the horizon depending on the observer’s location. They may have measured with their fingers to find the angle between the stars and the horizon. For this reason, sailors used the isba as the unit for measuring the angle between the Pole Star and horizon. The arc which measures the elevation of the pole from the horizon, thus expresses “degree of latitude” or “degree of longitude”. This measurement is not expressed as a degree, but simply as the distance to the equator or the meridian. However, a complete knowledge of this qiyas concerning the Pole Star involves other elements of astronomical knowledge. For example, the stars near the Pole Star are also important. Actually, there is no star at the North Pole. Thus, sailors needed to know that jah is the Arabic name of the star which stands near the North Pole and jady is the name of Capricorn. (When both of them rise at same time, it is a good omen in Arab world.) This empty area can be separated into two parts. One empty part is called “eastern” and another empty part is called “western.” These directions may be indicated by an astrolabe or lodestone. However, due to the precession, the Pole Star is very close the real North Pole, and that is why the degree between horizon and Pole Star is almost the latitude on geography.41 There are three conditions that make the qiyas method useful. The first condition is weather. In order to take these measurements, a sailor would have to hold an instrument as steady as possible with hands and teeth. These instruments cannot be used well in strong winds and strong waves. Along with the qiyas of measuring the Pole Star, Arabic sailors used the 32 rhumbs with tirfa, zām, and qiyas. The qiyas of measuring the altitude of a star as a guide to latitude was

41 Yan, Dunjie 嚴敦杰, 1966, p.77‐88. ‐ 23 ‐

combined with the compass rose and the division of the ship into 32 parts. Also, the boat was imagined like the needle of a big compass on the open sea and the rhumbs were marked by constellations. For example, Farqadan (two stars near Ursa Minor) stood opposite the star Achernar (α Eridani). These stars represent the bow of ship and poop, respectively, but they are also used to mark directions. The second method of qiyas relied on Farqadan and Sulbar. The two stars of Farqadan rises at dawn with Libra (Zubanan) and Sulbar is the same star as Achernar. In the fettering method, Sirius) and al‐waqui (Vega), because Sirius is brighter , ﱢالشعرى) sailors preferred to use al‐shiʿ'rā and clearer to observe. According to Tibbetts, Arab sailors used the Pole Star as a standard, because Sirius and Vega stand at almost the same altitude of heaven for these three stars to form an isosceles triangle. Europeans calculated the “raising of the Pole.” This method is similar to the tirfa method of Persian origin. This method considered the distance travelled by a ship and calculated the time in terms of zām which had been used for a long time in the Indian Ocean. One zām equal three hours, eight zām equal twenty‐four modern hours and eight zām is one isba. Until the fifteenth and sixteenth century, though, zām were also an angular measure for navigators, which meant the surface of the sea and was an arc unit in navigation.

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Figure 7: Diagram of Finding Latitude. When people stand at different laitutides and observe the same star, the star appears at different relative positions. In this example, the angle between the Pole star and the horizon is different for observers at A and B. Fettering There were other methods of using stars for qiyas measurements. These were used especially when the Pole Star could not be observed on cloudy days. For example, in the “fettering” method, sailors used familiar stars. Each particular star or constellation had links to other stars or constellations. By comparing the two observations, the sailors could determine the time. Stars observers also used this simple skill to memorize stars positions. In different times and places, different stars were used. Sometimes they used Achernar with the rising of Sirius and other times they used Achernar with the setting of Vega. Unfortunately, there is no system which covers the whole range of possibilities. As noted above, sometimes sailors used Vega and sometimes they used Sirius. In the sky, Vega and Sirius are at almost the same altitude. If one star can be observed, the observation of the other one will also probably be accurate. Ibn Mājid prefered to use Sirius as his standard when he sailed near Oman and the Persian Gulf. Moreover, the technique of fettering also has a similar meaning in Chinese. The word for fettering may be translated as qian 牽 in Chinese. This word also means “to hold up”, or “to tie

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together,” like the combination of stars on starry night. This word is connected with the qianxin ban 牽星板, the so‐called “star‐fettering boards” which are mentioned as navigation instruments in Chinese sources. In addition, it is could be possible that this device worked according to an underlying theory which was brought from the Islamic world.

Abdāl Another method presented in accounts of measurements of latitude is the abdāl. This method is used for two stars when they were at the same altitude in the sky. For example, Vega and Capella are two bright stars which stand at a suitable position.

Figure 8: Diagram for Finding the Meridian. When two bright stars stand on the same altitude, sailors could imagine the trangle for these two stars and make the meridian line. In this example, Vega and Capella mark the meridian. As a result, it is easy to observe the passage of the bright star and understand time.

These two bright stars are at almost same altitude. That is why abdāl relationships were related to the meridian. Sailors used these stars which stood at the same altitude to imagine the meridian line between these two stars. Sailors could tell time according to which star was on the meridian or by which lunar mansion crossed this line. For this reason, the lunar mansions also become very important in the knowledge of Arab navigation technology.

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Navigational Miscellany Other knowledge was also useful to navigation. Much of this information was not astronomical. This general knowledge related geography and meteorology (weather patterns) to navigation. The tides, winds, landmarks, water‐coloration and other geographic features all together were called ishārat. For sailors, these were all the basic things they needed to know, such as the coastline, the sand colors in different depths of the levels of the sea. The ishārat also included familiar situations of the appearance of the shore when they were close land and what features could first be seen on the horizon. All the descriptions of Red Sea include some of these landmarks and features. For example, the environment of the atolls near the Maldives are often described in detail. Moreover, the sea‐snake was listed as a common observation off the Indian coast when coming from Arabia. These descriptions even extend to cuttle fish and specific types of birds, like umm ṣanānī, the munjī and the kuraik which were easily identifiable. Another important element in Arab navigation was the use of bearings, which they called majra.42 The compass was used to know the direction and the compass needle identified the direction on the compass card. This card used rhumbs. When Europeans crossed the Indian Ocean, they used a magnetic compass needle or lodestone or some other compass‐like device, combined with the rhumb to avoid getting lost on the open sea. Arabs named these directions with reference to the image of the boat on open sea. In this picture, the boat was like a big compass needle and it was separated into 32 parts. Crossing the open‐sea was the most important and necessary situation for using lunar mansion as a navigational skill. For sailors, sailing along the coastline was the best and safest way to avoid getting lost. However, when navigational technology developed and people want to save time, sailing on the open sea became a progressive choice.

42 Tibbetts, G. R. 1981, p.290. ‐ 27 ‐

Monsoon

Monsoons of the Arabian Sea The season for leaving from Arabia to India was determined by the southwest monsoon. The southeast monsoon began in March on the eastern shores of Africa. This wind normally blew eastward until June. This wind drove boats to reach the coast of Gujarat until late May or early June.43 For the return trip, navigators relied on the Northeast monsoon. This monsoon blows from mainland India and carries no rain. This monsoon began in early October in the Sind province of Pakistan and reached Ceylon. This monsoon blew until March in the next year. Sailors who sailed the Arabian Sea were familiar with this monsoon as well.44 Together, the two monsoons made a “round trip” which was dependant on the calendar and the sailor’s country of departure.

Monsoons of the Indian Ocean For the navigators who sailed the Indian Ocean, the winds also represented the directions. For Indian navigators, there were some mnemonic devices which associated the technical terms for the winds with the areas which lay in those directions. Sailors were familiar with the monsoons and their directions. For example, they knew the strong monsoon from the south‐ west drove ships to Malabar and Lakshadweep, and the name of this wind of meant “cloud” in Tamil Nadu.45 In addition, some winds were even named by the morning rising and evening setting of specific stars from horizon. For example, the Arab katru (Arab wind) was named after the setting of the star Arab (Antares). Likewise, the Sothi katru (Sothi wind) was named after the rising of the star Swati (Arctrus). Moreover, some winds were associated with some specific areas, like the ela‐katru which meant “the Ceylon wind” in southern Tamil Nadu and the northwesterly Poysachi vara, which meant “Persian wind” in Konkan. 46

43 Tibbetts, G. R. 1981, p.364‐367. 44 Tibbetts, G.R. 1981, p.371. 45 Arunachalam, B. 2009, p.206. 46Arunachalam, B. 2009, p.206. ‐ 28 ‐

Figure 9: Wind‐Compasses used around India.Different regions of India referred to the directions by different wind names. (source: B. Arunachalam, 2009, p.19. )

Wind is an important condition for navigation, not only to power the ship but also to tell sailors the direction. The monsoon is the main power to cross the open‐sea but in many specific places, the winds are different with respect to information for navigation. Thus, according to different harbor, Arunachalam reported each direction named by the wind. When a full set of eight directions can be found, these are another type of compass and can be called “wind compasses”. We know this information not only from Chinese sources, but also from Islamic material. They called the southwest monsoon from Arabia to India was the Rih‐al‐Kaw or the Rih al‐ ‐ 29 ‐

Dabur.47 The southwest monsoon began in March at the east African coast and grew strong and spread until June to arrive at the Indian peninsula. On the other side, the Arabic name is for the northeast monsoon Rih Azyab or the Rih al‐Saba. This monsoon sprang from the mainland with no rain and began in early October in Bengal in winter. When the season was coming, the monsoon could change, and that mean it was time to sail. And that is what the Swahili called rih al‐qila ain for “wind of two sails”. There are some empiprical knowledge about sailing in Indian Ocean. When sailors departed from China, it was hard to predict the exact day or time of wind change from north to Northeast wind. Normally they departed before May, as experience. If they departed later than the tenth of June, on they could not arrive at Hormuz on this voyage.48 On the other side, from Omen or Yemen on the Arabic peninsula back to India, boats can almost sail all year, especially from May to July, when the Southwest wind was strong in the summer season. In this situation, sailors went from Red Sea back to India, from Ceylon to Sumatra. Due to the Northeast wind, it was also hard to sail when departing in November. The monsoon method was used well and it can also be seen in this record on maps. There are two figures that point out how the monsoon important on was this sea route. Moreover, it also marked the wind direction and seasons. This is a map by Herman Moll (1654‐1732), who was an important geographer in England in seventeenth century. Although this map was published in eighteenth century, the information of monsoon shows us sailor still relied on this to navigate. This map contained the Indian Ocean, the monsoon direction, and eight‐seven newly discovered island.49 To understand wind represents a huge intellectual endeavor which drew from a wide range of sources. However, when the voyage is considered holistically, the monsoon winds were still important even until the eighteenth century.

47 Tibbetts, G. R. 1981, p.368. 48 Tibbetts, G. R. 1981, p.372. 49 According to the introduction of exhibition “Geo|Graphic: Celebrating Maps and their Stories,” held at the National Library Board, in Singapore. ‐ 30 ‐

Figure 10: Map of Asia Herman Moll (1715). This figure was taken from the exhibition “Geo|Graphic: Celebrating Maps and their Stories,” held at the National Library Board, in Singapore. This map marks the wind direction by the arrows and also describes them with a month. The monsoon corresponds with the departure and return season. The Northeast wind is in the winter and the Southwest wind is in the summer in the Southeastern area.

Figure 11: Map of Asia Herman Moll (1715). This figure is also taken from the exhibition, “Geo|Graphic: Celebrating Maps and their Stories,” held at the National Library Board, Singapore. The monsoon winds follow the rule that the Northeast wind is in the winter and the Southwest wind is in the summer. The regularity of these winds helps navigators cross the Arabic Sea from India. ‐ 31 ‐

Lunar Mansions: The lunar mansions were a kind of ancient technology of observation. There were two methods to account for its origins. In the first method, ancient astronomers observed the circle of moon and its relationship to the ecliptic. Then they separated the circle into the stations based on the average number of days the moon took to pass by all the stars. By the other account, the method developed from observing the bright stars on the horizon during the dawn and evening. In the course of the average lunar month, the astronomers checked which lunar mansions the moon occupied before sunrise. The distance the moon moved every day of the lunar month was identified as a lunar mansion. Before the Islamic Empire grew up, the Bedouin had used this system and called it anwā’ Moreover, some Indian systems of astronomy from pre‐Islamic dates also used Lunar Mansions. For some specific areas in India, astronomers chose this method to the observe pathway of the moon. Thus, when Muslims found this Indian knowledge, they adopted the idea and mixed together the astronomical systems to develop a new idea. After Islam learned of this astronomical system from India and combined it with their knowledge, they established the idea as famous and transported it to Europe. Thus, since time is an important condition for navigation, how to measure time become a very necessary issue for ancient people. In order to understand the importance of the lunar mansions, the use of time in navigatation must be introduced, and in order to understand how understand time measurement, a simple introduction to lunar mansions must be made.50

Definition of Lunar Mansions The lunar mansions are some asterisms in some specific star groups in constellations through which the moon’s path goes.51 There are twenty‐eight constellations and the moon stays near each of them every night of the month. This observation could have been used to construct calendars, or at the very least to know the time in the calendar. Each civilization had similar observations to understand the position of the moon or sun in the sky in order to count

50 North, J.D. 1990, p.246. 51 Arunachalam, B. 2002, p.29. ‐ 32 ‐

the time and position in the calendar. What is most interesting is that several old civilizations have systems of constellations similar to the lunar mansion and most of them counted twenty‐ eight such asterisms. For example, there are twenty‐eight constellations in Chinese, which are called ershiba xinxiu (二十八星宿, twenty‐eight star lodges). They estimated that the lunar orbit was completed in about twenty‐eight days. Each mansion was named with the suffix xiu (宿, “lodge,” in the sense of nightly lodging) and the name of each of these “nights” began with a word with different meaning. Ancient Chinese astronomers separated the sky into twenty‐eight regular parts. Working with the four traditional directions, each direction has seven mansions in the north, east, west and south. Likewise, Babylon, Egypt, India, Arabia had a similar theory of observation for time keeping and made similar divisions of the night sky. In Middle Ages, especially from tenth to fifteenth century, several notable arabic scholars studied astronomy and mathematics. For example, Abu al‐Qasim al‐Zahrawi, in his work the The Goal of the Wiseman), translated into Latin as Picatrix (The غاية الحكيم) Ghāyat al‐hakīm Painter) and his contemporary Ibn al‐Hātim both took similar approaches to the subject of lunar mansions. They both probably borrowed from Abd al‐Rahmān III al‐Nāṣir (891‐961). He is probably also the Arabic source of the Alchandreana collection of Latin texts. This simple astrology book makes predictions and relates them or astronomical technologies. However, most importantly for the purpose of navigation, Ibn Habīt (dates) determines the hour of night by lunar mansion. Each lunar mansions crosses the meridian when it culminates, or reaches its heighest point from the horizon. Ibn Habīt measures the number of lunar mansions which have culminated since sunset. The total number of lunar mansion is twenty‐eight in the have fourteen on night time and another fourteen hidden under the horizon in day time.52 Each mansion rising after sunset indicates another hour that the path through the heavenly hemisphere has rotated around the earth.53

Simple Astronomy Astronomers observe heavenly bodies as they move from east to west. The sun and moon are the most obvious and useful heaven bodies in the sky. People used different devices such as

52 Samsó, Julio 2008, p122‐123. 53 Samsó, Julio 2008, p.123. ‐ 33 ‐

sundials to track the sun’s position across the sky. Over the course of a year, the sun traces a path which we call the ecliptic. Along this circle, there are twelve separate areas and which are called zodiacal signs. These experiences with observation develop alongside astrology but the use of the zodiacal signs in astronomy can be traced from 626 BC in Babylon.54 On the other hand, astronomers observed the moon’s path at night. After collecting observations for a long time, people found that the moon moved by a particular space in the heavens every day and in a little more than twenty‐seven days it moved through a complete circle. This path on which the moon moves is the lunar orbit. These lunar observations and the establishment of a lunar calendar to account for them occurred in almost every ancient civilizations. These spaces are called “lunar mansions” in Arabic and “star lodges” (xinxiu, 星宿) in Chinese. Both of them separated the ecliptic into twenty‐eight constellations and chose a bright star for each asterism. However, not every ancient culture separated twenty‐eight constellations. For example, there were both twenty‐eight and twenty‐seven such constellations in ancient India.55 The ershiba xinxiu in Chinese also combined with four traditional directions: east, south, west and north. Each direction contains seven of these constellations, is associated with a symbolic animal, and has a particular color. By this system, east was green, south was red, north was black, west was white. These colors were often arranged in each of the four directions, with yellow (often associated with the Middle Kingdom) at the center. In this way, the cardinal directions could be interpreted as an early pattern of five elements (wu xing 五行) in ancient China.56 The lunar mansion could function like today’s “hour.” All the celestial bodies move around the Earth in twenty‐four hours. Sailors supposed a meridian line ran from the point directly above the observer’s head (the zenith) and the point on the horizon between the rising and setting of the ecliptic. Sailors observed which lunar mansion crossed this line and in this way used the lunar mansions for timekeeping.

54 MicahRoss, “The Role of Alexander in the Transmission of the Zodiac,” in Alexander the Great and Egypt: History, Art, Tradition (Wiesbaden: Harrassowitz, 2014), p. 289. 55 Chen Zungui 陳遵媯, 1985, p.55. 56 Chen Zungui 陳遵媯, 1985, p.76. ‐ 34 ‐

The lunar mansions are very useful for timekeeping in low latitude areas (tropics). In the area about twenty‐three degrees to the North or South of the equator, daytime and nighttime are almost equal in all the different seasons. For nearly all of the year, there are fourteen lunar mansions in the sky above the horizon and fourteen below the horizon. When astronomers observed a new lunar mansion cross the meridian, they knew it meant that another lunar mansion rose in the east seven lunar mansions earlier and another lunar mansion set in the west seven lunar mansions later.

Development of Astronomy Several cultures existed on the sea routes of the South China Sea and the Indian Ocean. Each of these cultures represented the stars with a different name or even considered a different area of the sky to be associated with the asterism. Although the names of the stars or asterisms were different in different civilizations, these civilizations still used the same theory to observe them and keep time with them. For example, suppose a navigator found the moon stood in Gemini. The position of Gemini in the sky is the same as jinxiu 井宿 of the Chinese the forearm”) among the Arabic lunar mansions. The“ ,الذراع) lunar mansions and also al‐dirâ‘u exact star which the name of the lunar mansion indicated may vary between these cultures, but the Arabic and Chinese systems identify roughly similar regions of the sky. The table below attempts to sort out the names of stars, asterisms, and constellations. The definitions were different and sometime covered different areas. This table roughly explains the names and relations of the zodiacal signs and lunar mansions, mainly according to the orbit from sun and moon.

‐ 35 ‐

Table 1: Comparison of Western Constellations and Stars with their Equivalents in Chinese and Arabic systems.

Zodiac Sign

Western bright Western Chinese Chinese star in constellation constellation bright star Arabic star name each name name name constellation

Aries (Ram) 牡羊座 Adla

畢宿五 Taurus (Bull) 金牛座 Aldebaran(Juday) Bixuiwu

昴宿星團 Pleiades (The Najm (Thurayya) Nymphs) Maoxiu xintuan

Gemini 雙子座 (Twins)

Cancer (Crab) 巨蟹座

軒轅十四 Regulus (The 獅子座 Leo (Lion) Little King) α Xuanyuan Leonis shisi

Spica (The Ear 處女座 (室女 角宿一 Virgo (Virgin) of Grain) α 座) Virginis Jiaoxiuyi

氐宿四 Libra (Balance) 天秤座 β Libra Zubanan Dixiusi

Farqadan

Scorpio 天蝎座 Iklil

‐ 36 ‐

Antares (“Equal to 心宿二 (Scorpion) Mars”) Qalb Xinxiuer α Scorpii

箕宿三 Sagittarius 射手座 (人馬 ε Sagittarii Qaw 座 (Bowman) ) Jixiushan

雷壁陣四 Capricornus 摩羯座 (山羊 δ Capricorpi al‐Jady 座 (Goat‐horn) ) Leibizhepsi

Aquarius 水瓶座 (寶瓶 虛宿一 (Water β Aquarii 座) Bearer) Xuxiuyi

右更二 Pisces (Fish) 雙魚座 η Piscium Yougener

‐ 37 ‐

Table 2: Comparison of Western, Chinese and Arabic Twenty‐eight Lunar Mansions systems.

Twenty‐Eight Lunar Mansions

Chinese Chinese Western Chinese twenty‐eight bright star constellation constellation Arabic twenty‐eight lunar mansions lunar name name name mansions

角宿 室女 α al‘Awwa

Jiaoxiu (αVirgo ) 室女座 Virgo (Virgin) 亢宿 室女 χ (Virgo)

Kangxiu (χVirgo) al‐Simâk 氐宿 天秤 α

Dixiu (αLibra) 天秤座 Libra (Balance) al‐Ghafr (Libra) az‐Zubânay

al‐Iklil

房宿 天蝎 π al‐Kalb

Fangxiu (πScorpio) 天蝎座 Scorpio 心宿 天蝎 σ (Scorpion) (Scorpio) Xinxiu (σScorpio)

尾宿 天蝎 μ

Weixiu (μ Scorpio) aš‐Shaula 箕宿 人馬 人馬座 γ Sagittarius Jixiu (γSagittarius) (Bowman) (Sagittarius)

‐ 38 ‐

斗宿 人馬 ψ an‐Na’âjim Douxiu (ψ Sagittarius)

al‐Baldâh

Sa‘d ad‐Dabih 魔羯座 Capricornus 牛宿 魔羯 β Sa‘d Bula‘ (Goat‐horn) (Capricornus) Niuxiu (β Capricornus)

Sa‘d as‐Su‘ȗd

女宿 寶瓶 ε Sa‘d al‐ahbija

Nuxiu (ε Aquarius) 寶瓶座 Aquarius 虛宿 寶瓶 β (Waterbearer) (Aquarius) Xuxiu (β Aquarius)

危宿 寶瓶 α

Weixiu (α Aquarius) al‐Fargh ăl‐awwai

雙魚座 Pisces (Fish) (Pisces) al‐Fargh ‐ al‐altânî

室宿 飛馬 α

Shixiu (α Pegasus) Pegasus 飛馬座 (Winged 壁宿 飛馬 γ Horse) (Pegasus)

Bixiu (γ Pegasus)

窐宿 仙女 仙女座 η Andromeda Guixiu (η Andromeda) (ChainWoman) (Andromeda)

‐ 39 ‐

Pisces (Fish) 雙魚座 Botn al‐Hȗt

婁宿 白羊 β aš‐Šaaatanî

Louxiu (β Aries) 白羊座 Aries (Ram) 胃宿 白羊 35 (Aries) al‐Butain

Weixiu (35 Aries)

昴宿 金牛 17 al‐Turaijâ

Maoxiu (17 Taurus) 金牛座 畢宿 金牛 ε Taurus (Bull) al‐Dabarân (Taurus) Bixiu (ε Taurus)

雙子座 al‐Dak‘a

(Gemini)

觜宿 獵戶 λ

Zixiu (λ Orion) 獵戶座 Orion (Hunter) 參宿 獵戶 ξ (Orion)

Shenxiu (ξ Orion)

‐ 40 ‐

井宿 al‐Han‘a 雙子座 Jingxiu Gemini (Twins) (Gemini)

al‐Dirâ‘u

鬼宿 巨蟹 θ an‐Natra 巨蟹座 Guixiu (θ Cancer) Cancer (Crab) (Cancer) al‐Tarf

al‐Gabha

獅子座 Leo (Lion) al‐Zubra (Leo)

室女座 al‐Sarfa Virgo (Virgin) (Virgo)

柳宿 長蛇 δ

Liuxiu (δ Hydra)

星宿 長蛇 長蛇座 α Hydra (Sea Xinxiu (α Hydra) Serpent) (Hydra)

張宿 長蛇 ν

Zhangxiu (ν Hydra)

翼宿 巨爵 巨爵座 α Crater (Mixing Yixiu (α Crater) Bowl) (Crater)

軫宿 烏鴉 α 烏鴉座 Corvus (Crow) zhenxiu (α Corvus) (Corvus)

‐ 41 ‐

Table 3: Comparison of Circumpolar Western Constellations and Stars with their Equivalents in Chinese and Arabic systems.

Other constellations (star sign)

Western Chinese Bright star in Chinese constellation constellation each bright star Arabic star name name name constellation name

大熊座 Pole Star, 北極星 Ursa Major Polaris, α Jah (Great Bear) Daxiong zuo Ursae Minoris Beiji xin

al‐Shai

al‐Fulani Tujahuka

al‐Mikh

御夫座 五車二 Auriga Capella al‐Aiyuq (Chariot) Yufu zuo α Aurigae Wujuer 牧夫座 大角星 Boötes (Ox‐ Arcturus α Simak driver) Mufu zuo Boötis Dajiao Xin

Eridanus 波江座 Achernar α (Eridanus Sulbar Eridani River) Pojiang zuo

大犬座 Canis Major

(Great Dog) Daquan zuo

天狼星 Sirius α Canis al‐Tir (al‐Shira) (al‐Abbur) Major Tianlang Xin

船底座 老人星 Carina (The Canopus α Suhail Keel) Chuandi Zuo Carinae Laoren Xin

‐ 42 ‐

獵戶座 Orion (Hunter) al‐Jauza (al‐jabbar) Liehu Zuo

半人馬座 Centaurus Himaran (Centaur) Banrenma Zuo

半人馬 α 星 Zalim Banrenma α Xin

半人馬 β 星 Ma Qal Banrenma β Xin

Cassiopeia 仙后座 al‐Naqa ( al‐Sanam) (al‐ (Seated Kursi) Queen) Xianhou Zuo

Pegasus 飛馬座 (Winged Furu Horse) Feima Zuo

天琴座 Lyra (Lyre) Tianqin Zuo

織女星 al‐Kathir (al‐Nasr) (al‐ Vega α Lyrae Zhinu Xin Kufait)

天鷹座 Aqulia(Eagle) al‐Taliq Tianyin zuo

Cygnus (Swan) 天鵝座 Shalyaq

Virgo (Virgin) 處女座 al‐Simak

In order to cross the open‐sea using the abdāl method, sailors needed to understand stars’ position in the heavens to know the direction. This table presents the Arabic lunar mansions ‐ 43 ‐

and the day of the calendar on which they can first be observed rising in the east when the sun sets. According to these observations, sailors knew their position in the calendar and how many days they had been sailing from the asterisms of lunar mansions.

Table 4: Comparison of Arabic Lunar Mansions with their Calendar Dates.

Name Day

1 aš‐Šaaatanî 156

2 al‐Butain 169

3 al‐Turaijâ 182

4 al‐Dabarân 195

5 al‐Dak‘a

6 al‐Han‘a 221

7 al‐Dirâ‘u 234

8 an‐Natra 247

9 al‐Tarf 260

10 al‐Gabha 274

11 al‐Zubra 287

12 al‐Sarfa 300

13 al‐Awwa 313

14 al‐Simâk 326

15 al‐Ghafr 339

16 az‐Zubânay 352

17 al‐Iklîl 1

‐ 44 ‐

18 al‐Kalb 13

19 aš‐Šaula 26

20 an‐Na’âjim 39

21 al‐Baldâh 52

22 Sa‘d ad‐Dabih 65

23 Sa‘d Bula‘ 78

24 Sa‘d as‐Su‘ȗd 91

25 Sa‘d al‐Ahbija 104

26 al‐Fargh 117

al‐Awwai

27 al‐Fargh ‐ al‐Altânî 130

28 Botn al‐Hȗt 143

Lunar Mansions in Different Cultures Modern scholars have discussed where the system of organizing the twenty‐eight constellations originated. Chinese scholars have the idea that these constellations came from China and could be traced back to 239 B.C. in the book 呂氏春秋.57 Recently, archaeologists found a coffin which was carved with the earliest depiction of these twenty‐eight constellations. The archaeological discoveries can be traced even further back to the Warring States Period about 433 B.C. Archaeologists have found a grave from this time with a dragon drawn on the right and a tiger is on the left side. 58This pattern marks the origins of, or at least the oldest source for, the four directional animals in ancient China. The other two sides are the Vermilion Bird 朱雀 in the south and the Black Tortoise 玄武 in the north. In the middle of this pattern stands the word dou 斗 which may have some connection with “seven stars of the northern

57 Shun, Xiaochun 孫小淳, 1996, p.76. 58 Chen, Zungui 陳遵媯, 1985, p.75. ‐ 45 ‐

spoon”, (Beidou Qixin 北斗七星),or the Big Dipper. The twenty‐eight constellations surround this word. Not only Chinese scholars hold this opinion on the origins of the twenty‐eight constellations, but the Japanese scholar Shinzo Shinjo 新城新藏 also has a similar idea. He proposed that the twenty‐eight constellations developed earlier than the zodiacal signs, because the twenty‐eight constellations marked the lunar path and the new moon is defined by 朔 (Shuo, the first day of Lunar Calender). Moreover, no vestiges of this system can be found vestige in Babylon. The Chinese system of lunar mansions is different from Arab or Indian systems. For example, the twenty‐eight constellations used in China do not include Capella. In addition, Arabs and Persians developed their systems of twenty‐eight constellations after India. Chinese astronomers related the direction of the Big Dipper to the seasons of the year: 斗杓東指，天下皆春；斗杓南指，天下皆夏；斗杓西指，天下皆秋；斗杓北指，天下 皆冬。59 (When the bucket points east, it is spring under heaven; When the bucket points south, it is summer under heaven; When the bucket points west, it is autumn under heaven; when the bucket points north, it is winter under heaven.) In this way, when they saw the direction of the bucket of the dipper at sunset, they used it as an estimation of the progress of the sun through the zodiacal signs. Even today, if we observe at night time, it is not too hard find that Ursa Major still points to different directions in different seasons. Chinese astronomers did not limit their association of the sun’s progress through the ecliptic to the direction of the Big Dipper. They also combined the lunar mansions with the cardinal directions so that each group of seven lunar mansions be associated with the same direction.

59 Lu, Dianjie 陸佃解, 1966, p.21. ‐ 46 ‐

Figure 12: The Carving on the Coffin from the Grave of Marquee Zenyi in Modern Hubei Province. This carving represents the original pattern of the twenty‐eight constellations. Figure from Bo Shuren 薄樹人 editor,“The History of Chinese Astronomy” 中國天文學史. Taipei, Wenjin chubanshe 文津出版社, 1996, second page of colored illustrations.

Other scholars have concluded that the lunar mansions were created somewhere before they existed in China. According to the Japanese scholar Iijima Tadao 飯島忠夫, the eclipse cycle of the calendar needs seven leap years in each nineteen‐year cycle. In Greece, Meton was the first who developed this type of system in 433 B.C. This development was spread around the world, through the influence of the explorations by Alexander the Great, King of Macedonia. For this reason, Iijima believed that the twenty‐eight constellations originated in Babylon.60 Likewise, L. Weber made a hypothesis that the twenty‐eight constellations came from India, because the first constellation in India is mao 昴 but in China the constellations begin with jiao 角. According to this theory, mao used to mark the spring equinox and was used earlier and was used more than a thousand years earlier than jiao.61 The lunar mansions gave astronomers a frame of reference for observation. The lunar mansions occupied the lunar path in the sky, and for this reason, the constellations on this path become the important background to identify lunar position on the sky. Moreover, astronomers

60 Shun, Xiaochun 孫小淳, 1996, p.82. 61 Chen, Zungui 陳遵媯, 1985, p.54. ‐ 47 ‐

defined these asterisms in a specific order. They were not just randomly arranged background, and the order made it easy to predict the next lunar station. In addition, the phase of the moon changed day‐by‐day. According to the paragraph above, the moon moved along the lunar path as it changed phases. These movements made the lunar calendar. Navigators counted time according to this calendar and observed the wind to decide the dates of their departure and return. During the voyage, they used lunar mansion and other constellations to count time and figure distance, and they checked the phase of moon to know the day. The lunar path appears in two diagrams from the Song Dynasty of China. Obviously, the asterisms are listed in the margin alongside the lunar path. Ancient Chinese astronomers put the names of the stars, the names of the twenty‐eight constellation, and the number of degrees in the map. In the title, they described the directions from northeast to southwest. The arc in the middle of diagram represents the lunar path, and the twenty‐eight lunar mansions are listed on the diagram in order.

‐ 48 ‐

Figure 13: New Description of an Armillary Clock (Xin Yixiang Fayao 新儀象法要) by Su Song 蘇頌. This depiction of the armillary clock describes the twenty‐eight constellations and the lunar path. This figure describes Northeast direction and start from the Jiaoxiu 角宿.

‐ 49 ‐

Figure 14: New Description of an Armillary Clock (Xin Yixiang Fayao 新儀象法要) by Su Song 蘇頌. This figure connects with the previous figure and describes the remaining lunar mansions and the rest of the lunar path. It starts from Guixiu 奎宿 and shows the Southwest direction.

‐ 50 ‐

These two figures present the twenty‐eight Chinese lunar mansions from New Description of an Armillary Clock (Xin Yixiang Fayao 新儀象法要) published in the Song Dynasty. In the middle of these figures, arcing to the north or the south, runs the lunar path. According to observations of the moon’s position, the lunar movement was sometimes faster and sometimes slower. By modern astronomical knowledge, the orbit of the moon around Earth actually is ellipse not the circle. Due to this reason, observations from Earth find that the lunar velocity is not always the same. However, anlient astronomers found the lunar velocities depending on the area of the lunar path. To mark these areas of the night sky, astronomers selected the average lunar circle, separated it into twenty‐eight parts marked by asterisms, and chose the brightest star in each lunar mansion. In this way, people of different cultures selected different areas for each of the lunar mansions and sometimes even the brightest stars are different, too. Conversely, some cultures could choose the same areas and same brightest stars, too. Thus, scholars argue that thirteen Arabic lunar mansions are one and the same with Chinese lunar mansions, and sometimes even have the same bright stars. 62 Alternately, there were twenty‐eight lunar mansions in India, but they seem to have had twenty‐seven lunar mansions in ancient times. In addition, for a very short time, Chinese had twenty‐seven lunar mansions, not twenty‐eight. 63 If even the number of lunar mansions can change, different people have different definitions of the area of each lunar mansions. No matter what area of the sky astronomers chose for each asterism, the used the same theory to make twenty‐eight lunar mansions as the background by which to observe the lunar path and predict sun and moon’s position for making the calendar. Astronomy: Mansions mark day of month The moon passes through the lunar circle around the Earth in about 27.3 days and the moon passes through all of its phases in about 29.5.64 Ancient astronomers used the phases of the moon to make the lunar calendar and establish a guide to tell people when to sow crops or sail. Astronomy and calendars even developed into astrology to predict fortune. According to the phases of the moon, astronomers decided that the odd months had thirty days and the

62 Chen, Zungui 陳遵媯, 1985, p.54. 63 Chen, Zungui 陳遵媯, 1985, p.55. 64 The annual report of Astronomy in 2014, 2014, p.1. ‐ 51 ‐

even months had twenty‐nine days. Although most people no longer work in agriculture, now people still use lunar calendars to celebrate holidays or do some religion activities, such as the Chinese New Year and Muslim Ramadan. In addition, not only did the phases of moon indicate the dates and time but they were also a sign of the rise and fall of tides. The seamen had learned that the moment of high tide changed every day. They knew well how the tides change with new moon and full moon.65 As an example of the phases of the moon, consider this table of moon phases for November, 2014. According to records of the Taipei Astronomy Museum, November 1, 2014 is the ninth day of the seventh intercalary month and the end of November is the ninth day of the eighth month of the lunar calendar. The phases change regularly and follow the twenty‐eight lunar mansions for a circle. In this figures, the moon enters a new lodge of the lunar path every day and the phase of moon changes every day.

Figure 15: Phases of the Moon in November 2014. This record is from the Taipei Astronomy Museum. It presents the lunar changes according to each day.

65 Arunachalam, B. 2009, p.208. ‐ 52 ‐

Connection of Lunar Mansions to Navigational Astronomy Time is an important condition for navigation. Sailors observed heaven bodies to define time. The lunar mansions are markers of the moon’s orbit. Compared with the other stars, the lunar mansions are bright and easy to observe along the path of the moon, as it changes position every day. The moon is the only satellite of the Earth and it orbits the earth in about twenty‐eight days. On average, the moon will visit each of these twenty‐eight asterisms called lunar mansions one‐by‐one during the days of the month. Moreover, the phases of the moon helped astronomers to make the lunar calendar. Navigators occassionally needed to know the day of the month when they were beginning a voyage. In this way, our ancestors calculated the days of the month by the moon. The day of the month can be checked by the moon. For example, the day of the full moon marks the middle of Chinese and Arabic months. After the day of the full moon, the moon will move to another mansion, and work same way to account with time. More often, though, navigators needed to tell the time in smaller increments like hours or zām. Telling time in small units was useful for correcting the path caused by wind which blew in a direction only approximately the same as the direction the navigator wanted to go. Knowledge of the lunar mansions was useful to sailors because these stars rise in the east and set in the west. A new lunar mansion rises in the east and one sets in the west nearly every hour. In this way, astronomers can use the stars on the ecliptic (Yellow Path) to tell the time. Navigators not only used the moon as a standard but also used other asterisms in some specific star groups to tell the time. When the moon was available, its motions could be used but lunar mansions could be used without the moon. When ships sailed on the ocean especially on the open sea, sailors needed to know that how long have been sailing. For this reason, checking the time was a necessary and important thing for navigation. The angle of stars from their rising in the east through their zenith and to their setting in the west not only tells the time, but is also connected with the direction.

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Use of Lunar Mansions in Time‐Keeping How the sailors observed the movement of the lunar mansions movement to tell time must be considered. Although the stars rising in the east may rise from different precise positions on the eastern horizon but all the heavenly bodies move around with North Pole in the amount of time indicated by eight zām. Sailors measured the angle of the star from the horizon and separated one day into eight parts. Hence, as the figure below presents, navigators understood time by stars movement from east to west. Moreover, the stars further away from the ecliptic can also tell the navigators the direction like compass by their risings and settings.

Figure 16: The zām of measurement time system worked with the movement of the stars. Sailors measured time by the stars according to this system.

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Conclusions

How to Use Lunar Mansions No matter where the lunar mansions are from, different cultures used different asterisms to define the areas of the lunar mansions. However, the phases of the moon resulted in about twenty‐eight days defining the circle of the lunar path. Astronomers chose at least one bright star in each asterism. These were convenient for observations and different cultures have different bright stars. However, all these cultures relied on the same theory of lunar mansions to mark the motions of the heaven bodies, especially the sun and moon, to make the calendar. First, the lunar mansions defined the path of the moon’s orbit and coincided with the phases of the moon, which concluded in about twenty‐eight days. Astronomers used these areas as a frame of reference to predict the moon’s position and to infer the sun’s position. From this information, they knew the calendar date. Secondly, lunar mansions were closely associated with specific directions. For example, Chinese Lunar Mansions represent four directions for each seven mansions. The grip of the Big Dipper (Ursa Major) defined seasons, and could be combined with traditional mythical animals (dragon, phoenix, tiger, and turtle) which stand for East, South, West and North. Thus, Chinese astronomers used the movent of heavenly bodies to understand time and combined this astronomical technology with geography to know directions and seasons. This idea can be traced back to 430 BC by archaeological discoveries. However, the Book of Changes (Yi Jing 易經) developed this ideology even earlier, around the Western Zhou Dynasty (1044‐771 BC). The Book of Changes combined geography and astrology, but more importantly, it represents the ancient philosophical theory that man is an integral part of nature, subject to the “reaction of human and heaven” (Tian ren he yi 天人合一). Hence, Liu Xin 劉歆 (50‐23 BC) organized Triple Concordance (Santong Li 三統曆) according to the Spring Equinox and Autumnal Equinox developed twenty‐four solar terms (Ershisi jieqi 二十四節氣) by observations of the heavenly bodies.66 The solar positions that decided the twenty‐four solar terms indicated agricultural

66 Translation after Nathan Sivin, 2009, p.79‐80, but the understanding of the source must be supplemented with Han Dynasty texts.. ‐ 55 ‐

activites and reflected the ideology of the reaction of human and heaven, which developed even into astrology, social structures, and Chinese culture. On the other hand, the near east Babylon Israel, everyone used a purely lunar calendar. They used each new moon as the first day of a new month, and counted twelve months in a year, without any intercalary months. Thus, the lunar path in the sky become very important for observations.

Relationship with Navigation Direction and time are important information for navigation. For time, navigators might ask what day is today? What time is it? And how long have been sailing? All these questions could be answered by stars. By observing the solar and lunar position, astronomers could know the Spring Equinox, Autumnal Equinox, Winter Solstice and Summer Solstice. Astronomers recorded more accurate measurements to make calendar. Different cultures made different types of observations. After finding what day it was, that the second necessary condition was to know the “hours”. In ancient India, zām is one kind of unit of hours. They separated a day into eight parts, which means a zām equals three hours. By this method, the first zām was counted from sunset. At this time, the astronomer chose the bright star of the lunar mansion which appeared at sunset. When this bright star passed forty‐five degrees from the horizon, that meant that the second zām started. Then midnight began at hundred thirty‐five degrees, and so on, as presented in the figure below.

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Diagram 17: The zām system. The system of dividing the sky into zām worked with the motion of the stars and sailors used it to reckon the angle of a star from the horizon. Thus, according to this rule, the timing of midnight also forms the meridian for navigators.

By this method, sailors could watch the bright star which appeared on horizon and according to the angle of horizon, they know how long they had been sailing. It is an easy and important way for measure of time by stars. And the bright stars of the lunar mansions are good for this method. Stars were used for navigation, but there were several methods for navigation, especially for crossing the open‐sea. One of famous method is qiyas, according to which the angle between Pole Star and horizon was equated with the latitude. The second method is abdāl, which used pairs of stars. For example, when the two bright stars Capella and Vega stand at the same altitude of horizon there will an imaginary meridian through the zenith. It is convenient for sailors to watch bright stars cross the meridian to understand time. This method works not only with bright stars but also with lunar mansions. This method could work with zām and was an easy way to measure time. When navigators sailed from east to west, they watched the movements of the heavenly bodies as timekeeping. This type of observation was not only dealt with time problem, but also solved the longitude issue, until John Harrison (1693‐1776)

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invented durable clocks called chronometers in the seventeenth century. Then, this invention made time more precise and reduced the danger of navigation. 67 in Arabic, meant “tie” or “bond” in English. Moreover, it was ابدال ,The abdāl method translated as qianxin (fettering, or tie heaven stars) 牽星 in Chinese. It could be that this method dragged or tied one bright star to another. It was convenient to memorize all the relative positions of the stars in heaven, so that his method could be used even without star map. It called “The Song of the March of the Heavens” (Butiange 步天歌) by a ancient Daoist named

Danyuanzi 丹元子.68 This method is still used for astronomical observations now, for example, when novice astronomers are told to follow the handle of the Big Dipper (Ursa Major) to find the Pole Star. In the case of the Big Dipper (Ursa Major), the handle was an important indicator of time for the Chinese. The handle will point to the east at 23:00 in the spring time. Combined with the Chinese double‐hours (shichen 時辰), this marks the first hour of day (zishi 子時). Following the same rule, the handle points north, west and south on the first double‐hour of the summer, autumn, and winter, respectively. Some Chinese sources mention qianxin with the qianxin ban 牽星板 (star fettering board), which was a specific instrument for navigation. This record also can be found in Chart of Sea‐ Crossing by Fettering Stars (Guoyang Qianxin Tu 過洋牽星圖, 1621),which existed in the Wubei Zhi 武備志 (translation, 1621). These sources also report that this device worked with 過洋牽星 術 and that the unit of the angle is zhi 指. Navigation is a complex, technological science, which includes several fields of knowledge such as astronomy, timekeeping, ship‐building technology and geography. In the middle ages, the Indian Ocean sailors realized the monsoon rule: there is a north‐east wind in winter and south‐west wind in summer. Navigators familiar with these winds decided the departure and return days. Moreover, the coastline view, plants and animals such as different fish and seagull are also kinds of sign for sailors to gain an idea of their location. In conclusion, sailors accumulated experiences over several generations. By the middle ages, these navigation technologies had been developed well enough to sail the open‐sea. At that

67 Dava, Sobel, 1995, p.89 68 Zheng, qiao, 鄭樵 1987, p.539‐540. ‐ 58 ‐

time, they knew the days and season of the monsoon to decide departure and return days. They used lunar mansions and zām as timekeeping devices. They were familiar with the rising and setting of heaven bodies and recognized directions by their movement. Corresponding Chinese sources record how sea voyagers might have sailed in the Pingzhou Ketan, 69 Clearly, the sun, moon, and stars play an important role for navigation. After solving the problems of crossing the open‐sea at night, sailors used geomorphology, plants such as seaweed, animals like birds and fish group or sea‐snake in different places to identify location when the ship was close to the coastline, as Tibbetts translates form the Ibn‐Majid manuscript. Arabic sailors also worked experiences gathered over a long period of time and their methods were not like the traditional Chinese methods. In particular, the Chinese used the genlu 更路 or zhenlu 針路 and the compass needle for sailing.70 Thus, to understand these methods of maritime technology, another important element of navigation is instruments. After basic studies, there were some devices which were used on the sea road. The first instrument is the qianxin ban which can be found in Chinese sources. The second instrument is the compass, which was an important device for navigation for a long time, and actually can be found in several types. The third type of instrument is the astrolabe, which is a fantastic piece of art that not only indicates time but also identifies the location by stars. These tools, like the different methods for navigation, exist in different cultures. And these tools will be introduced in Chapter Three.

69 Zhu ,Yu 朱彧 1995, p.1644. 70 Huang, Shenzhang 黃盛璋 2008, p.122. ‐ 59 ‐

Instruments

Introduction Like history, technology is a human endeavor. During the history of navigation, whenever explorers found some new region of the globe, they used their experiences to relate these new places to what they already knew and they used their navigational observations to define its location. However, back to the reality of the situation, when a navigator sailed in unknown ocean, he would first use the al‐qaid method, also known as “fettering” or “qianxin” (牽星) to define his location in a way which could be related to maps and other geographical knowledge. In this way, the sailors used the known to define the unknown. This practice even extended from the terrestrial sphere to the celestial sphere. As northern sailors travelled south, they found new stars, and they added these stars to maps in a way which fit with known practices. For example, several constellations of the southern hemisphere were named for navigational tools such as “Sextans” and “Telescopium.” These names are evidence of the importance that navigational devices played in sailing. Astronomy developed along with maritime technology in each culture and they even influenced each other. For navigation, time and direction are the important conditions. Sailors in the Arabian Sea and Indian Ocean knew several types of “compass rose,” or standard divisions of the dirctions. The first type was the Chinese compass rose. The Chinese developed these divisions to work with the magnetic needle compass. In contrast to the Western standard, the needle was assumed to point toward the south and the directions were marked with the Earthly Branches (Di Zhi 地支). Other cultures developed different types of compass rose. Sometimes, they used stars to mark the directions and sometimes they named the directions with the winds. For example, the Gujarati Hindu compass rose indicated the directions according to the postions of the stars which rose and set on the horizon and the Tamil compass rose used winds. Regardless of culture, these techniques can be called the “sidereal compass rose” and the “wind compass rose” to distinguish them from the Chinese magnetic‐needle compass.

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Further west than the Indian Ocean, there was another famous and important device named the “astrolabe” (from a Greek word which means “star taker”) which could be traced to ancient Greek about 200 BC. This instrument was used to measure the angles of stars from the horizon. This device was developed to its greatest extent in the Islamic world of the Middle Ages. Islamic astronomers relied on this device to tell time and directions according to the stars. The observers used the astrolabe to measure the angle of stars from the horizon (or from the zenith). Depending on the latitude, though, stars reached different altitudes. Thus, astronomers had to make different astrolabes for different locations. And they also developed a particular astrolabe for navigation and work in the Arabian Sea and Indian Ocean. Some astrolabes had different plates. These plates could be changed so the astrolabe could be used at multiple latitudes. The standard method of knowing the latitude (and which plate to use with the astrolabe) was to measure the angle of the Pole Star from the horizon. The Pole Star is directly overhead (at the zenith) when the observer stands at the North Pole; it is on the horizon when the observer stands at the horizon. This method not only could be used with an astrolabe, but also with another device called the “qianxin ban” in Chinese and “kamal” in Moorish and Arabian culture.71 This instrument could measure the angle of the Pole Star with a board. This board had a hole in its center and a rope extended through this hole. Sailors measured the height of the Pole Star to understand their latitude. They used the rope to keep the board a fixed distance from the observer’s eye. The observer measured the elevation of the Pole Star by comparing its position with this instrument. The instrument was very useful to measure the angle and the navigator related this measurement to basic astronomy to know the latitude. Moreover, there were several types of this instrument in different materials throughout history. One type of star‐fettering board was a set of square boards. They used different boards of different sizes. Each board fit the angle between the Pole Star and the horizon at particular latitude. Another type of star‐fettering board had one board but several different knots on the rope. Through experience with sailing in different locations, the sailors assinged a known latitude to different distances of the board from the observer’s eye. Although that these instrument existed in

71 Needham Joseph 1978, p.574. ‐ 61 ‐

different types, they all used the same idea: to measure the angle between the Pole Star and the horizon to identify the latitude in the open sea. Thus, since instruments played an important role in navigation, the compass rose, the astrolabe, and the qianxin ban (kamal), should be explained in detail. These explanations will show how these devices were used by sailors in the Araban Sea and Indian Ocean. These explanations will also consider how these navigators used these tools with ideas from different cultures. These ideas include their concepts of time and direction. After that, a reconsideration may be made of how different cultures travelled in these waterways by instruments and built wide commercial network in the Middle Ages.

Compass Rose and Magnetic Compasses When we try to classify the objects called compasses, we can sort out two types depending on whether or not they have a lodestone (or magnetic needle). The first type of objects has needle in the middle to tell sailors the directions. This object can be better described as a “magnetic compass.” The other object often called a compass has no needle and only contains the information around the compass. It could include winds, stars or some particular marks. For the sake of clarity, this object can be called a “compass rose.” The compass rose is one of common instruments for navigation. It is normally round shape with some necessary marks on the circle to tell navigators different information. As for the marks on the circle, they could be the names of asterisms or directions or durations of travel or even names of ports. As noted above, the types of compass rose actually existed in different forms which ought to be collected to understand how they told navigators necessary information (and what navigators considered necessary information). The sailors working in Southeast Asia, the Indian Ocean, the Arabian Sea, and Persian Gulf of fifteenth century used the same techniques, but they expressed these ideas in different ways. The magnetic compass can be traced back to Han Dynasty in ancient China.72 At this time, there were several types of compass which were used on land. In the Song Dynasty, the Pingzhou ketan mentioned that sailors used a compass on cloudy day. Thus, as these sources

72 Cheng, Jianjun 程建軍, 2005, p.2. ‐ 62 ‐

describe, the magnetic compass played a more and more important role for navigation. For instance, the The Customs of Cambodia records many details about the culture of southeast Asian countries, especially in the ancient Vietnamese Kingdom named Champa 占城. This ancient kingdom was also called Zhenla 真臘 by some Chinese sources. In addition to this early report, Gung Zhen 鞏珍 (fl. 1430) a companion of Zheng He, wrote the Record of the Foreign Countries in the Western Oceans (Xiyang fanguo zhi 西洋番國志 1434). He left some record of compass readings at different locations in this book.73 Moreover, in his Chart of Sea‐Crossing by Fettering Stars, he included some information about the compass for navigation. In short, he stated that the compass could help sailors to identify directions. Some civilizations, such as the Gujarati, used stars as an marker for the directions74. Other cultures, such as the Tamil,75 used winds to mark the directions of the compass rose. No matter how they were marked, the directions were necessary information for sailors and sailors often used multiple systems. This use of multiple systems occured because sailors accumulated experiences with natural phenomenon over a long period of time. Just as sailors will stop at “any port in a storm,” they will also use any system of direction to help them find their path and avoid getting lost on the sea. This old sea‐road began in South China, passed through Sumatra, rounded India, went past Hormuz, and ends in the Islamic countries. Not only did these regions use two sorts of compass – one with a magnetic needle and one without– but several types of compass rose existed in the different cultures. For this reason, it is not too hard to realize that there were different devices used in different cultures. It is also meant that there were lots sailors sailing and communicating with each other. This is interesting because we can observe how people face the natural world and how to solve the same problem in different cultures, sometime with the same results, sometimes with distinctive differences.

73 Needham, Joseph 1978, vol.4, p.492. 74 Arunachalam, B. 2009, p.212. 75 Arunachalam, B. 2009, p.212. ‐ 63 ‐

A. Magnetic Needle Compass (Chinese) Generally speaking, ancient people had stronger feelings of connection with natural world than many modern people. Our ancestors accumulated generations of experiences. In this way, they developed an empirical understanding of nature. For this reason, they associated natural phenomena with different signs. For example, when the Sirius rose from the east at dawn, it mean that the season of flood was coming for the Nile River. In ancient China, people developed the particular idea that each kind of heavenly phenomenon represented some type of human activity. They separated heaven into several parts to reflect countries or states in the world. This method of distinguishing parts of the heaven and earth was called fenyie 分野. According to Huainanzi (The Masters/Philosophers of Huainan 淮南子 before 139 BC), there were twenty‐eight fenyie along the White Path (the path of the moon)76 and twelve fenyie along the Yellow Path (the ecliptic). The twelve fenyie also could be called fenci 分次. To describe the motions of the sun, moon and planets, astronomers distinguished twelve parts of ecliptic.77 It was an ancient method of separating the parts of the sky in ancient China and even could be traced to about the Yin or Shang Dynasty, 殷商.78 The most important idea, though, is that these divisions could be combined with people, states, and earthly events. Thus, they developed the ideology of traditional Chinese astronomy by combining human activites and heaven.79 Each of the twelve ci 次 also connects with twenty‐eight lunar mansions, and they also combine with the Book of Changes. It should also be noticed that these stars reflect the directions, and construct the basic compass shape.

76 As noted above, observations by astronomers using the lunar path may be related to the fact that the average orbit of the moon is about twenty‐eight days. On the other hand, some scholars such as think that the number of twenty‐eight comes from the orbit of Saturn, which also took about twenty‐eight year for a circle. 77 Cheng, Jianjun 程建軍, 2005, p.110. 78 The twelve is order from Xinji 星紀、Xuanxiao 玄枵、Juzi 娵訾、Jianglu 降屢、Daliang 大梁、Shichen 實沈、 Chuenshou 鶉首、Chuenhuo 鶉火、Chuenwei 鶉尾、Shouxin 壽星、Dahuo 大火、Ximu 析木. 79 Zheng, Huishen 鄭慧生, 2006, p.56. ‐ 64 ‐

Figure 18: This figure is the basic compass shape of the twelve ci and combine with Chineses twenty‐eight lunar mansions, Book of Change. 80

In the Han Dynasty, the lodestone was combined with the compass rose and the magnetic needle was made like a spoon shape. In ancient China, people used to find the Pole Star according to the Big Dipper (Ursa Major) and from this known position they understood the directions. In memory of this connection between the stars and directions, they made the lodestone in the shape of a spoon to represent the Big Dipper in the sky. They put the polished spoon in the middle of the compass rose to create and early magnetic compass in Chinese.

80 Cheng, Jianjun 程建軍, 2005, p.111. ‐ 65 ‐

Figure 19: Magnetic Spoon Compass of Han Dynasty, First Century A.D. South is on the right hand side of the board. This design reconstructed by Wang Zhenduo 王振鐸 (Li Shuhua 李書華, 1959, illustration 4) .

Aside from the directions, the compass rose also had twelve chen 十二辰，which meant the twelve hours in a day. These hours names used the earthly branches, 地支, as names. The branches are named zhi 子, chou 丑,yin 寅, mao 卯, chen 辰, si 巳, wu 午, wei 未, shen 申, you 酉, xu 戌, hai 亥. Later, the magnetic water compass appeared in the Song Dynasty. In this type of compass, the spoon changed its shape and even the plate developed into a different form. The Mengxi Bitan 夢溪筆談 (Dream Pool Essay about 1086‐1093) mentions that when people used the water compass, they prepared a bowl of water to make the magnetic indicator float on water. 81 For this type of compass, a needle‐shaped magnet is more efficient than a spoon shaped magnet. This type of compass is a technological advance, because water has less friction than a solid. This method existed in several types, such as a version in which the magnetic needle was

81 Shen, Kuo 沈括, 1966, vol.24, p.7. ‐ 66 ‐

in the shape of a fish.82Until Yuan Dynasty, Guide through the Forest of Affairs 事林廣記 (Shilin guangji, between 110‐1250) shows us there were other similar devices and that the fish‐shaped need could be made of wood or even made replaced by a turtle‐shaped needle83 The magnetic water compasses also used a special type of compass rose. This division of directions started with the twelve Earthly Branches but excluded wu 戊 and ji 己. It took all also ten Heavenly Stems. Finally, it added the four cardinal directions from the Book of Changes: qian 乾 kun 坤 xun 巽 gen 艮. These are numbers from Book of Changes to account. All twenty‐ four of these marks go around the compass to name the direction which the lodestone indicates. This kind of compass was used in navigation and still with loadstone needle in the middle of this device. People could see the direction as the needle pointed to the marks around the edge of compass. This navigation method was called zhenlu 針路 (compass‐needle route ) or genlu 更路. Sailors could follow the needle and the mark to know the direction and avoid getting lost.

Figure 20: A Compass using the Zhenlu Navigation Method. Photo taken at the Quanzhou Maritime Museum, March 2015.

This navigation method is useful for coastline sailing. By following the needle and the marks around the compass, the sailors could know their course. These marks around the compass

82 Li, Shuhua 李書華, 1959, p.28. 83 Li, Shuhua 李書華, 1959, p.32. ‐ 67 ‐

were similar to the units of division of the circle. Although the divisions were not very precise, they still could be converted to modern degrees. In some sea‐charts, such as the Chart of Sea‐ Crossing by Fettering Stars.This method of maritime navigation lasted for several generations and even produced a kind of guide book called Genlu Bu.

B. Zām Compass (India, Arabic) The path from the Persian Gulf, into the Arabic Sea, through the Indian Ocean, into a Southeast Asia and the South China Sea is an old sea route and people communicated by this waterway for generations. Sailing on this path in the open‐sea, especially at night time, was a big issue. Without the precisely reckoned longitudes and latitudes or the modern Global Positioning System, stars became a very important factor in solving this question. In this situation, different cultures used different methods to navigate. In the magnetic compass, Chinese navigators used a magnetic compass needle to identify the direction. Other civilizations such India and Arabia, used to use stars as guides for sailing. Different people made different choices in the bright stars which they used as guides. For instance, the star called “Rigel” by Arabs and Western seamen is called “Mageram” in Lakshadweep and this name means the “path‐finder” among Tamil seamen. Arabic seamen preferred to use a star called al‐ Deberan which was familiar to Indian sailors as “Strangel” but was not particularly important for navigation.84 In short, no matter what bright stars or asterisms they preferred to used, the different inhabitants all used stars as guiders for sailing. This sort of method of finding the direction by stars can be called a “star compass,” or a “sidereal compass.” Sailors from several cultures preferred this method over the Chinese loadstone needle compass. The star compass contained both direction determination and time measurement. That means the stars not only told the sailors their direction but also indicated for how many zām the ship had been sailing which was an important problem for navigators. To solve for the direction, navigators used the azimuth (that is, the bright star or constellation which crossed the meridian) or horizon stars to indicate specific stars on horizon which were paired with

84 Arunachalam, B. 2002, p.30. ‐ 68 ‐

directions.85 The next two figures reproduce the Gujarati Hindu star compass and the azimuth stars used in Indian stellar roses.

Figure 21: A Stellar Rose. These systems of directional notation originated in India and work with the names in figure 22. Together, they describe directions (Arunachalam, 2002, p.37).

Figure 22: Names of the Stellar Roses. This system originated in India and indicated directions. (Arunachalam, 2002, p.31)

85 Arunachalam, B. 2002, p.36‐37. ‐ 69 ‐

Figure 23: Azimuth Stars used in Indian Stellar Roses. (Arunachalam, 2002, p.37)

Figure 24: Gujarati Wind Compass (Arunachalam, 2002, p.21).

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Figure 25: Tamil Wind Compass (Arunachalam, 2002, p.21).

The stars which the compass presents can be used in all different places. This star compass was based on the rising of stars to identify direction. Hence, it was very possible that sailors observed these stars at specific time, especially at dawn and dusk.86 These particular stars or asterism do not have to follow any specific order, like the bright stars of Lunar Mansion. Depending on different traditions of navigation, different places adopted their prefered method to navigate. Sailors observed bright stars to know the direction. All these compasses actually work in stereographic projection. The compasses focus on a specific direction, which normally is north. After finding the direction where the stars rising from the horizon in evening, navigators can use the motion of these stars to measure how long they had been sailing. These observations worked with the zām system which was a unique measurement of time and mentioned last chapter. The next two figures explain the figures above in basic diagram. Different colors identify different stars on their paths. Their motion is limited to these paths and is presented in

86 Samsó, Julio 2008, p.123. ‐ 71 ‐

stereographic projection. These images represent the idea behind the star compasses in Indian Ocean.

Figure 26: Rotation of Stars from East to West. The different colors identify different stars, which rise and set across the meridian. Not only does it tell direction but they also work with the zām system.

Figure 27: Stereographic Projection of Figure 26. The projection of the stars on the plate shows directions.

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In this way, stars could indicate the direction for boats sailing on the ocean. Thus, the different areas are defined by different spaces on the heavenly sphere with reference to specific stars. And these directions are called “rhumbs” or “bearings” for navigation. This “star compass” could also be called a “star rose,” and it appeared earlier than the compass rose of the Chinese magnetic needle compass.87 There were with some bright stars which were consistently identified with rhumbs. Sailors identified directions by different stars according to different seasons. For instance, Rigel, Capella, Canopus, and Sirius were best used from December to February, whereas Arctrus, Spica, Corvus, Alpha, Beta Centauri and Acrux are good to observe in February to April.88 The sidereal rhumbs were set up by stars to define directions. This type of sidereal azimuthual compass rose can be traced for long time – even earlier than the measurement of the stars by angles but it is hard to find precisely the time when it appeared.89 What is known about this method can be traced to ancient theories of astronomy which originated in tropical areas. The ancient Persians described these directions with the word “hann” which may be the origin of the similar term “khann” on the Arabian and Gujarat coasts.90 In the same situation, sailors of different cultures could choose different bright stars as rhumbs to identify the direction. For example, Arabian sailors liked to use Al‐Debaran but Indian sailors liked to use the Pleiades.91 It so happened that, even in similar cases, people will choose familiar methods even though they have similar theories about the stars. Moreover, this sidereal compass not only tells directions, but these directions could also be used as specific channels for ships. For example, the island of Socotra which is in the northwest Indian Ocean and now belongs to Yemen had a pro sperous business trade. Because some particular islands and harbors developed trade with Socotra, these places entered the maritime technology. The star compass of Socotra uses the asterisms to tell the directions and associates the waterays with important harbors.

87 Arunachalam, B. 2002 p.38. 88 Arunachalam, B. 2002 p.37‐38. 89 Arunachalam, B. 2002 p.41. 90 Arunachalam, B. 2002 p.38. 91 Arunachalam, B. 2002 p.39. ‐ 73 ‐

Figure 28: Socotra Based Azimuthal Stellar Half Compass. (Arunachalam, 2002, p.40).

Figure 29: Socotra based Kutchi half star compass. (A) (Arunachalam, 2002, p.40)

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Figure 30: Socotra based Kutchi Half Star Compass.(B) (Arunachalam, 2002, fig 3.5, .40)

Astrolabe The astrolabe is an instrument used to calculate the days of the calendar and the hours of the day. Ancient people understood the change of seasons and the passage of time from generations of experience. By observing the sun, moon and planets for a long time, people collected their movements along a regular circle. Based on these studies, people combined the movement of the heavenly bodies and their knowledge of geography to invent an instrument which relates the place and time to the stars. Through the angle of the horizon and stars, observers can determine their latitude. Thus, the meridian, the horizon, the ecliptic, and even specific bright stars of constellations are used in telling people information about the time and location. These elements can even be used on cloudy days. 92 Because time and direction are important for navigation, the astrolabe was a great advantage. Since the astrolabe used stars to understand time and direction, it became the perfect device for sailing.

History, Greek to Arabic The history of astrolabe depends on understanding the stereographic projection and following the development of this method. The stereographic projection can be traced back to

92 North, J.D. 1989, p.211. ‐ 75 ‐

Greek astronomers, particularly Hipparchus. The works of Hipparchus have been lost, but another important source is the Alexandrian astronomer Ptolemy. This great astronomer wrote famous books in which he explored astronomical ideas. In the Almagest, Ptolemy presented an account of the motions of the celestial bodies; in the Planisphaerium, Ptolemy discussed the stereographic projection of the sky. Hermann of Carinthia (A.D. 1100—1160) was a philosopher, astronomer and writer. He translated the Quran and many Islamic books into Latin. At the same time (A.D. 1143), he translated the Planisphaerium into Latin. This translation introduced the method of stereographic projection and the idea of the astrolabe. John Philoponos wrote in Greek on the construction of instruments in sixth century, and Severus Sebokht wrote on the same topic in Syriac. Thus, through works such as these, knowledge developed simultaneously in Islamic and Western cultures. In the fourteen century, Geoffrey Chaucer wrote some notes on making astrolabes to his son Lewis. Through this English treatise, we can understand how the astrolabe worked in the Middle Ages. Thus, many scholars have read Chaucer’s account and realized how this instrument works.93

Parts of the Astrolabe The astrolabe can be described in three types. First, there was a linear, planispheric astrolabe. This kind astrolabe was hard to understand and rarely made. Secondly, there was the spherical astrolabe. It was also rare, but was more common than planispheric astrolabe. The third is the mariner’s astrolabe. Compared with other type astrolabe, this instrument was developed later but it was still used before the time of Columbus.94 All of astrolabes were marked with time and days but also noted the positions of bright stars. On the astrolabe, the signs of the zodiac along ecliptic were depicted. According to these zodiacal signs, an observer could understand the sun’s position through the calendar scale which lists the days and months of the year. Thus, with regard to the sun’s path, astronomers know that the solar path is a circle from zero degrees to three hundred and sixty degrees. Consequently, they separated the twelve parts of the zodiac into signs with thirty degrees each.

93North, J.D. 1989, p217. 94 North, J.D. 1989, p211. ‐ 76 ‐

They chose bright stars to mark each zodiacal sign, so it worked in a manner similar to the lunar mansions but this path specifically represents the sun’s position. 95 In the construction and function of the astrolabe, there are two most important parts. One is the rete which means “net” in Latin. This part could also be called the “spider” in other, mainly Arabic, sources. Several specific bright stars are marked on the rete to make a representation of the heavens. On the rete, there are also the celestial equator and the tropics of Cancer and Capricorn. The sun’s position will be on the equator during the spring equinox and autumnal equinox. About two thousand years ago, western astronomers found the solar position on Cancer and Capricorn during the summer and winter solstices. However, due to the procession, now these positions have already changed to Gemini and Pisces. After the rete, the second part is the set of almucantars, or circles of constant altitude. These circles extend from the horizon to zenith. There are several lines which connect with the azimuth and horizon. Thus, according to different latitudes, there are different projections. The areas which corresponded to the projections which were engraved on these plates were called “climates”. 96 It can be hard to distinguish between astronomy and cosmology in ancient times.97 Most of the western astrolabes and astronomical knowledge came from Muslim scholars, especially in Spain.98 Many methods of constructions and use of astrolabes were also translated from Arabic to Latin in the eleventh century.99 These translations clarified that basically, the astrolabe is an instrument which used a stereographic projection to present the heavenly bodies on a plate. This plate contained a star map and the ecliptic to predict sun’s movement. Due to the stereographic projection, the astrolabe depended on different latitudes which were called “climates”.100 The flat astrolabe can be separated into three major parts. The first major part is the rete, a represention of the heavens. The second part is a representation of the “climate”. This part fit

95 North, J.D. 1989, p212. 96 North, J.D. 1989, p213. 97 Lindberg, David C. 2007, p261. 98 Lindberg, David C. 2007, p262. 99 Lindberg, David C. 2007,p263. 100 Lindberg, David C. 2007, p264. ‐ 77 ‐

between the rete and the mater. The plates representing the climates had engraved lines that represented the different latitudes. Depending on the location of the observer, he could choose a different climate to match his latitude. The third major part was the “mater”, or mother. This was the base which held everything together. Sometimes, calendar information was inscribed on the mater. Then, there were minor parts which put the rete and the climates together on the mater. All the plates were held together by the horse and the pin. Also, the astrolabe could use sighting holes to measure the altitude of stars more accurately.

Figure 31: Parts of Astrolabe. The different plates of astrolabe, the rete, climates, mater, combine together and compute the time and direction. (J.D.North, Chaucer’s Universe, 1988, p.41.)

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These bright stars were mapped on the rete and a flattened representation of the sphere of the coordinate system was mapped on the climates. Because climates change with different latitudes, the observer used a different projection in different places, to give an idea of the latitude. Actually, there were several projectional methods for making astrolabe. Thus, the next figure will present one of the projection methods. The observer used the almucantars to identify the different altitudes. This part of the astrolave let the observers measure from the zenith to the horizon easily.

Figure 32: Stereographic Projection of Almucantars. These alumcantars are circles of equal size, parallel to the horizon (J.D.North, Chaucer’s Universe, 1988, p.53).

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Two images can show how the stereographic representation works. The first image shows the coordinate system of the sphere. The second image shows the projection according to the equator and the tropics. Imagine the Earth stands directly on its axis and does not lean 23.5 degrees. In this situation, the equator and tropics would be at a 90 degrees to the axis of the projection. This ideal projection method is shown in the figures below.

Figure 33: Stereographic Projection of Equator and Tropics (J.D.North, Chaucer’s Universe, 1988, p.52).

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In the third projection method, the lines of equal azimuth on the sphere are projected onto a flat plate. This method of projection is made without the almucantars. The angles between the intersecting circles follow from the sphere and are projected directly on the flat plate. They are stereographically projected on the flat plane.

Figure 34: Stereographic Projection of Constant Azimuth. The great circle passes from the zenith to horizon (J.D.North, Chaucer’s Universe, 1988, p.54).

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After understanding these different plates, we can put these plates together. The result is presented in the figure below. Hence, the observers could use this instrument to understand all the information from the front of the astrolabe. For example, the tropic of Capricorn and the tropic of Cancer told observers’ latitude. Moreover, the ecliptic indicated the sun’s yearly path through the heaven. The lines represent the coordinate lines and fit with the earth from observers location. Around the edge of the astrolabe, there was a ring which recorded information about time. The rete marked several bright stars to show the daily motions of stars and related with observer time.

Figure 35: The Rete of an Astrolabe. The rete includes the tropic of Capricorn, the tropic of Cancer and horizon line. (J.D.North, Stars, minds, and fate : essays in ancient and medieval cosmology, 1989, page on next 216.)

The rete is the plate by which the astrolabe indicated the position of the bright stars. As Tibbetts explains, the Arabic compass marked the rhumbs which were identified with specific bright stars. The use of the rhumbs represents a method of observing stars in the same manner

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as the astrolabe functions. In the next paragraph below, the importance of the compass rhumbs for Islam navigators are explained as the basis for time and direction.

Uses of the Astrolabe Astrolabes were actually capable of several functions such as finding the time, the date, the meridian, the longitude, the horoscope, or finding the position and time of eclipses. The relationship of several things makes the astrolabe like a computer which helped ancient people solve time and distance questions by referencee to heavenly objects. Thus, since the astrolabe played an important role in observation, the question about how to use it becomes a necessary to understand this device well. Tom Wujec has produced a clear, simple introduction to the astrolabe. 101 To use the astrolabe correctly, first select a star visible at night, for example, Deneb of the constellation Cygnus in the summer triangle. Measure the altitude of the star from the horizon. Hold the device up to read that it indicates twenty‐six degrees. Step three, identify the star on the front on astrolabe. In the same example, find the star Deneb indicated on the rete. Step four, after finding the star Deneb and move the rete with the sky. The altitude of Deneb should correspond to the scale on the back. After that, all these things should be combined together. The astrolable has a model of the sky and this should correspond with the real sky. Step five, move the middle ruler to mark the date and understand the time. Despite the simplicity of these instructions, there were many forms of astrolabe. Several different types of astrolabe are illustrated in The Planispheric Astrolabe.102 However, for these instructions, consider an astrolabe of the normal, flat circular form and assume the time is 09:54 of 24 January. By step one, find the scale on the back of the astrolabe and read the calendar. Find the solar position in the zodiac for the date. In this case, on the twenty‐fourth of January, the sun stands at Aquarius 4 1/2° (334.5°). Second, set the hours on the front to show that the time is 09:54 locally. Rotate the middle ruler and fit the scale. Each of these scales represents four

101 See Tom Wujec, Tom Wujec demos the 13th‐century astrolabe, TEDGlobal (available at https://www.youtube.com/watch?v=yioZhHe1i5M). 102 National Maritime Museum? This citation doesn’t make much sense to me. Can you include the image? ‐ 83 ‐

degrees. When the astrolabe is suspended in front of user, the hours before noon are shown on the left side and the hours after noon are on the right side. Then, keeping the time at 09:54, rotate the rete until the Sun’s position on the ecliptic circle falls on Aquarius 4 1/2°. Then, the plate will show the position of the stars in the sky. According to above explanation, observers could not only use the position of the stars to find the date and the time, but they could also rely on the date and time to read the difference of the model on the astrolabe from the actual image of the heavens. Obviously, the invention of the astrolabe relied on the development of astronomical knowledge. Meanwhile, it also represented how ancient astronomers found the rotation of heavenly bodies to connect with time. Thus, sailors could figure out time and directions by stars before methods of directly measuring latitude and longitude developed. On the complete astrolabe plate, there is shown a coordinate line with lines such as the tropic of Capricorn, tropic of Cancer, the line of equal azimuth, almucantars, equator, hour angle lines and the horizon. These lines compose all the conditions compressed by the stereographic projections. Moreover, the back of the astrolabe carried lots of necessary information for measuring the altitude of heaven bodies’s altitude such as time and degree. The rim has the twelve signs of the zodiac with thirty degree for each sign (360/12 = 30). These degrees often connect with Sun’s position. This also explains why observers use the dates according to the zodiac sign when using astrolabe, because these scales have a connection with the solar position. The quadrant of the astrolabe contains the stars’ altitudes and degrees, the “middle ruler” or the diameter of astrolabe corresponds with the sine of the altitude from horizon. The two opposite quadrants work with the middle ruler. The ruler not only points out the degree between the stars of heaven and the horizon, but it also tells the time. The quadrant of astrolabe carried most of the information, especially the stars degree and time.103 Thus, it influenced the development of the quadrant which was an important maritime instrument. And all of these instrument rely on the theory of measuring the altitude of stars.

103 North, J.D. 1989, page on next 217. ‐ 84 ‐

Just as they used the rete of the astrolabe, Arabic navigators used compass rhumbs which were similar to the rete on astrolabe. Moreover, the rose of rhumb lines which appears on the European chart can also be used to identify direction. Thus, the specific stars commonly found on the rhumbs are tabulated in the list below.104 1. Al‐Juday means the Pole Star. Arabs use this star as a standard to compare with other constellations. By the angle between horizon and the Pole Star, they can figure out the latitude. Although there is an empty point at the true North Pole, we still can find this on astrolabes and lodestones. 2. Farqadan and Sulbar. These are the rhumbs nearest to the Pole Star. The Farqadan are in Libra and Sulbar is Achernar. They rise with Aries or Taurus. Navigators knew that the Pole Star, Sulbar (Achernar) and Sirius made a triangle: Pole Star 12, Sulbar 3, Sirius 3. Pole Star 11, Sulbar 4, Sirius 4. Sulbar and Suhail are Achernar and Canopus. These two bright stars are also obviously stars used by navigators. Moreover, Libra and Achernar are opposite each other and Arabic navigators supposed these two stars were like the bow of the ship and the poop. 3. Al‐Nash and Suhail are the Crow and Canopus. Suhail is used as a guide in navigation. 4. Al‐Naqa and al‐Himaran are also opposite and one rises while another sets. When the Pole Star is at 11 isba and Himaran is at five isba on the sea, accurate latitude measurements can be taken from them. These measurements rival those taken from the Pole Star itself for they are on the horizon when the sailors are exactly over the South Pole. For example, when Suhail is setting and az‐Zalim is rising, this is because they have equal altitude and latitude. Then, we can know that the number of isba is about four and one‐quarter at Guardafui, which is close to the Gulf of Aden. And southern hemisphere stars can also be used to navigate with the wind and moon. Naqa and the Plough are also abdāl for sailors to measure latitude. Naqa and the Plough Star are at almost the same latitude. Sailors used these to check latitude. 5. Al‐Aiyuq and al‐Aqard. Aiyuq is Capella. Sailors used al‐Aiyuq and Vega in fettering. Vega is rising and setting together with Pleiades in thirtieth day of the year. The abdāl are valid for several days, some accurate for three or four or even six days. The measurements of Aiyuq and

104 Tibbetts, G. R. 1981, p.121‐156. ‐ 85 ‐

Vega were normally used to sail the Qulzum Sea, which contained the Red Sea and Caspian Sea of today. Because al‐Aiyuq is about 45 degrees from the North Pole, it was a special star used with the rhumbs to check position. 6. Vega and al‐Iklil. Vega rose with Sagittarius and Iklil rose and set with the Scorpion. At that time, sailors could possibly have relied on their experiences to navigate and did not know the theories discussed today. For this reason, Ibn Mājid could have had different definitions of the bright stars. In this part, Tibbetts reported that the Pole Star could be found according to Vega’s tail and is one of abdāl measure. 7. As‐Simakan and al‐Tir. These two stars are α Virgo (Spica) and Sirius. These indicate the direction of the as‐Saba wind that sailors measured in the Indian Ocean. Wind also played an important role because the monsoon winds were different in different season. For long voyages, from the coast of China to Aden, these are two important directions on the compass. 8. Thurayya and al‐Jauza. Thurayya, often called al‐Najm in the past, are known as the Pleiades today. Different boats used different zām to navigate. Thurayya was among the lunar mansions and was also used on the rhumb for navigation. 9. Al‐Tair was also called the outstretched eagle. Sometime, it was listed as al‐Hīrān on the rhumb. Sailors used this star for navigate in the Indian Ocean. This star is called Altair today and is bright and clear in the summer sky.

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Figure 36: Mother Plate of Astrolabe(J.D.North, Chaucer’s Universe, 1988, p.56).

Figure 37: Back of Astrolabe (J.D.North, Stars, minds, and fate : essays in ancient and medieval cosmology, 1989, page next to 217.

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Results: Latitude and Time Arabic technology, especially astronomy, absorbed knowledge from Babylon and Egypt. These places observed heaven bodies’ movements and understood their cycles, then they used this knowledge to make calendar. 105 The early Arabic astronomical knowledge was learned from India and the Sassanid Empire.106 No matter what kind of projection method represented the stars, observers relied on how those stars would change their positions when observed at different latitudes. The most obvious example for ancient astronomers is the definition of the tropic of Capricorn and the tropic of Cancer. Moreover, the ecliptic was defined by the idea that it was a straight line when it was presented on the stereographic projection of the rete. These reasons above explain how the astrolabe relied on stars, especially the summer and winter solstice which observed from sun and moon. Moreover, observers predicted the same eclipse at different times in different places. This change in prediction represents that astronomers understood the latitude at that time, such as the tropic of Capricorn and the tropic of Cancer, and called it a "climate". Thus, through accumulated observations of sky for several generations, ancient astronomers understood the winter and summer solstices, spring and autumn equinoxes and used them to make a calendar. They used to predicted eclipses to check whether the calendar and the time were reliable or not. Meanwhile, they confirm the calendar from eclipses in different places and realize the different longitude and latitude. This method can be used in the oppositeway, depending on what conditions the observers had. Suppose the observer knew the latitude then will know the time. It can be solved by measure the angle of star and horizon and get the degree from using astrolabe. In short, stars tell us time and we can use this to find locations.

105 Turner, Howard R. 2002, p.59. 106 Turner, Howard R. 2002, p.61. ‐ 88 ‐

About the Qianxin Ban and Liangtian Chi During the Ming Dynasty (1368‐1644), Zheng He 鄭和 (1371‐1644) conducted several maritime expeditions to Java, Sumatra, Malacca, Adam, Hormuz, Mogadishu and he is said to have reached as far as Mecca and the southeast Africa coast. Zheng’s first voyage took place in 1405, antedating Columbus’ (1451‐1506) famous voyage in 1492. It is said that Zheng used a particular method named qianxing shu 牽星術 to find the locations of his ships in the open sea; this technique involved in the use of a navigation tool called the qianxing ban 牽星板. Historical documents suggest that this device was composed of twelve different sized squared boards. The navigator would choose the board of a size suitable to the altitude of the star and thus could know where the ship was located in the ocean. Some historians have suggested that during the Song Dynasty (960‐1279) a kind of instrument named the liangtian chi 量天尺 was used for the same purpose. It looked like a ruler designed to observe stars and located the whereabouts of the sailing ship. Several attempts have been made to discuss the structure and the function of the liangtian chi. Yi Shitong 伊世同 has discussed how the Liangtian chi can be traced from the Wei, Jin, and North‐ South Dynasty (220‐589). Wang Lixing 王立興 mentioned that the liangtian chi has different types, for example, to measure shadows or to be used in fortune telling prectices.107 Wang Lixing discusses the liangtian chi among other astronomical instruments of the Ming Dynasty, while Yan Dunjie has researched the possible Arabic origins of the qianxing ban by focusing especially on the units of measurement of the device.108 Furthermore, Hsu Meiling , Sen Tansen , and Tien Jukang have discussed the early fifteenth century navigation in general. They discuss cartography, the use of the magnetic compass, and other instruments. When they discuss the possible channels of communication between the western world and the Song Dynasty, they establish the social context of these cultural transmissions and mention that Arabian businessmen had frequent connections with China. These interactions were especially visible in Quanzhou 泉州.

107 Yi, Shitong 伊世同 1989, p.358‐380; Wang Lixing 王立興 1983, p.122‐189. 108 Hangyun Shihua Bianji Xiaozu 航運史話編輯小組 1978, p.170‐189; Yan Dunjie 嚴敦杰 1966, p.77‐88. ‐ 89 ‐

These studies, however, cannot fully answer the question of how Zheng He navigated. Firstly, Zheng He’s records do not mention the liangtian chi. Moreover, it is even doubtful whether the liangtian chi was really a navigational instrument or if it had anything to do with the qiangxin ban. Secondly, an instrument alone was not enough to provide all the necessary information for the navigator to locate the ship in the open sea. The Pingzhou Ketan contains a description about how sea voyagers might have navigated. 109 That is to say, the navigational instrument had to work with the geographical and astronomical knowledge of the navigator before he could use it to locate his position. Therefore, sea charts may have been involved in the calculation. Thirdly, the Islamic influence on Chinese navigation techniques prior to the Ming Dynasty must be considered.

The Liangtian chi Guang Zhi Yi 廣志繹, a geography notebook, which was authored by Wang Shixing 王士性 (1547‐1598) and printed in the beginning of Qian Dynasty, contains the following description of the liangtian chi: 石綱為之者，石至數十丈，今尺塊不存，不知移於何處。城外繁臺，土人 念「繁」為「博」，亦未審其義所自始。或云即梁孝王平臺。又云師曠吹 臺，上有大禹廟，貌「河、洛思功」字，然廟貌狹，不稱所以祠禹者。周 公測景臺110在登封五十里村中，舊郜縣也，對箕山許由冢，有所遺量天尺

存，其所竪小石碑，果夏至日中無影。111 It was made of stone and measured several tens of zhang 丈, but today the ruler has disappeared, and one does not know where it is. There was

109 Zhu, Yu 朱彧 1995, p.1644. 110 The Tower of Zhou Gong is an instrument for measuring the sun’s shadow at Yangcheng 陽城, modern Luoyang 洛陽, this structure was revonated by Guo Shoujing 郭守敬 (1231‐1316), the Chinese astronomer, engineer, and mathematician of the Yuan Dynasty. He devised the “simplified instrument, (jianyi 簡儀)”, a precursor of the equatorial mountings for telescopes. His calendar, the Shoushi calendar 授時歷, was used for 363 years, the longest period for which a calendar was used in China. His works continued some ideas of Shen Kuo 沈括 (1031‐1095) and was influenced by Islamic science. He erected a 40 foot gnomon, which stood upright in a niche, and measured the shadow along the horizontal, graduated stone scale. 111Wang Shixing 王士性 1981, p.38. ‐ 90 ‐

a “fan tower” outside the town. Local people read [the word] “fan” 繁 as “bo”博, [but I] never found the meaning and origin [of these words]. Some other people called it the “Flat Tower of Xiao‐wang of the Liang Dynasty,” or named it “Shi Kuan Chui Tower”師曠吹臺. There was a temple named the “Great Yu” 大禹 temple on the top of the flat tower. However,the temple looks too small and does not look like the Great Yu type (?). The “Tower of Zhou Gong”周公測景台 is in Fifty Li Village, the old name of Kao County; facing the Xu Yu grave on Mount Ji, there was a liangtian chi; it was built as a stele, and actually casts no shadow on the Summer Solstice. The excerpt seems to suggest that the liangtian chi was a kind of ruler used to measure the shadow of a pole or a tower. Such a large and heavy instrument could not be used on a ship. Moreover, it was apparently an instrument used to determine time and not the location. In a different text, the phrase liangtian chi seems to represent a different instrument. An excerpt from the Jiean Laoren Manbi 戒庵老人漫筆 by Li Xu 李詡 (1506‐1593) reads: 紫薇殿東小室曰壺房，即浮漏堂，內有銅人一，銅壺五，曰日天壺，曰夜天 壺，曰平壺，曰萬水壺，曰分水壺。每逢日月蝕前三日調壺，則置銅人於萬 水壺上，面南抱箭，箭又名 量天尺，長三尺一寸，鐫晝夜時刻，上起午正， 下盡午初。112 The eastern chamber of Zi Wei’s 紫微 Palace Hall was named the “Vessel Room”, and also called the “Hall of the Floating Clepsydra.” There was a copper man inside, and five copper vessels named the “Ri Tian (translate) Vessel,” the “Ye Tian (night pot) Vessel,” the “Ping (day pot) Vessel,” the “Wan Shui (ten thousand water) Vessel,” and the “Fen Shui (division water) Vessel. [Time‐keepers] check these vessels three days before an eclipse of the sun or moon. [They] put the copper man on the Wan Shui

112 Li, Xu 李詡 1982, p.112.Wuzheng 午正 is the time from 12 p.m. to 1 p.m. Wuchu 午初 is the time from 11a.m. to 12p.m. ‐ 91 ‐

Vessel, holding an arrow and facing the South. The arrow is also called the liangtian chi; its length is three chi (尺) and one cun 寸; [it is used] to record the day and night time, from midday to the afternoon. Here, the liangtian chi was apparently related to a clepsydra combined with a sundial. Another excerpt from Qing dynasty source reads: 明渠仲寧滕縣人，精通地理，永樂間召試之，用量天尺度地之物，曰其下有

石如虎，掘之果驗，授本科訓術渠兆昌隆慶舉人113 Gu Zhong Ning, a person from Teng county who lived in Ming dynasty, was an expert in geography; he was tested in the Yong Le period (1403‐1424). He used the measuring instrument named liangtian chi to locate objects in the soil; he announced that there was a stone tiger under the ground; indeed after digging it, it was confirmed. Authorities gave him the title of Juren. This account shows that a Ming Dynasty man who was familiar with geography used an instrument named liangtian chi to locate a buried object. This kind of instrument seems not to have been used for navigation. One more relevant text from the Guangzhi yi is as follows: 南告縣舊治是也。予至其地，有二臺存焉。其南一臺，琢大石為之，上狹下 闊，高丈餘，廣半於高。中樹一石碑，刻曰『周公測影臺』。臺北三丈所， 復有一臺，約高三丈餘，壘磚為之。其北之中為缺道，深廣二尺許，下列石 為道，直達於北，約五丈許。石上為二小渠，渠側刻尺寸甚精密，最北一石 為二小竅以出水。詢其土人，云故老相傳為量天尺，又以為銅壺滴漏114。考 之縣志，此名觀星臺，亦周公所築。然予見其刻尺寸，所書特今文耳，恐非

出於周公。115

113 Ji, Huang 稽璜 1988, p.3778. A juren (舉人), in the Ming and Qian dynasty, was a successful candidate of the imperial provincial examination. 114 It is one kind of water clock. According to Joseph Needham, this instrument could possibly be from Mesopotamia. 115 Wang, Shixing 王士性 1981, p.38. ‐ 92 ‐

In Nan Gao County, there were two towers; the south one was built of big stones; its top was narrow and its bottom was wide; it was more than 1 zhang high, and its width was one half of its height. In the middle of it, a stele was erected. An inscription on it stated: ‘The Tower of Zhou Gong’. To the north of this tower there was another tower, about three zhang 丈 high, and made of bricks. There was a road, two chi deep, made of stone and going north, for about five zhang. On the top of the stone, there were two channels for water. For details [I] asked the local people, and they said that old people called it liangtian chi. They also called it a tong hu di lou 銅壺滴漏 and it is a kind of water clock. According to the history of the county, this tower for observing stars was built by Zhou Gong . However, the inscriptions on it are in a modern script, which I am afraid is from Zhou Gong. This text states that there were two towers whose function was to measure the shadow like the sundial and also to keep time by means of a water clock. One of towers had an instrument named liangtian chi and it also contained a clepsydra for time‐keeping. This passage suggests this kind of Liangtian chi had two channels inscribed with measurements. So, this instrument could be used to measure the shadow and the time, but apparently could not be used during voyages. The instrument mentioned in the excerpt abover was built in the Ming Dynasty. However, Yi Shitong 伊世同 suggests that the instrument could have appeared as early as the Tang Dynasty. 116 The author suggests that the prominent Yuan Dynasty astronomer Guo Shoujing 郭守敬 had modified the ruler, and used it not only for observing stars but also for measuring shadows. It remains unclear how this kind of liangtian chi could be used for navigation. Wang Lixing 王立興 states that different instruments are described in different classical books and tries to reconstruct them. He makes a list to

116 Yi, Shitong 伊世同 1989, p.358‐380. ‐ 93 ‐

compare the differences in shadow‐measuring in different historical periods.117 However, he does not discuss in detail the connections between the instruments with the navigational devices. The excerpts discussed above show that there were different kinds of liangtian chi Most of them were used to measure shadows. Could there be any modifications of such instruments used for navigation? How can it be possible that no description of a suitable specimen exists today? To conclude, it seems unlikely that any modifications of liangtian chi could have been widely used as a device for navigation.

What is the Qianxin Ban? According to Joseph Needham (1990‐1995), the qianxing ban was possibly transferred from the Arab world. The prototype was an instrument named the “cross‐staff”, “Jacob’s staff”, or the “kamal.”118 The suggestion looks reasonable, given that merchants from Islamic countries were doing business between Europe and China from ancient times. It is not difficult to imagine that they became familiar with this maritime navigation instrument in their frequent travels by sea. In addition, the Portuguese used a device similar to the “kamal” in the Mediterranean.119 Based on these reasons, the origins of this instrument should be considered. Ancient people collected experiences that could be used as rules of thumb for using the stars. These rules and relationships may have developed from using the hand as a tool for measuring arcs in the heavens. In such a situation, the finger was an obvious unit of measurement. This use may have had one origin which was communicated widely. Linguistically, the unit of fingers appears. As viral in south coast of Indian, dhru in Gujarat, kau in Kavaratti, isba in Arabic, and zhi in Chinese.120 However, identifying the first people to use their fingers as measuring units is difficult. Perhaps, several different cultures even solved the same problem in the same way.

117 Wang, Lixing 王立興 1983, p.122‐189. 118 Needham, Joseph 1978, p.574. 119 Arunachalam, B. 2002, p.44. 120 Arunachalam, B. 2002, p.42‐43. ‐ 94 ‐

The clues about the word kamal, that it was not originally an Arabic word. Actually, the which means “arc”. This kind of ,(کمان) Arabic word was a corruption of the Persian word kamān instrument could have been made of shell‐work in Tamil and Maldivian area.121 To summarize, the viral measurement was used to measure spherical arcs and these measurements worked with zām. This is the traditional maritime technology which measured the sailing time‐distance or how long the ship had been sailing.122 Here, as mentioned before, one isba equals eight zām. For technically, the unit converted from isba is not fingers, but the arc of the sky which corresponds to those fingers. That was why according to this theory, zām could represent the sailing‐distance. No matter whether it was called the kamal or qianxin ban, this instrument measured the angle between stars and horizon. Actually they existed in several forms. The different forms represent the different developments of several maritime cultures on this sea‐route. As examples of these different shapes, some typical types may be discussed. First is the board with a regular size and a string tied with knots. Secondly, there was the set of different sizes of boards. The different sizes if the boards size progressed by a specific unit and the string did not have any knots. Thirdly, there were sets of different sized boards which also had knots on the straight line.

A. Knots G. Ferrand assembled the sources from 1500 AD which represented the simple kamal. The descriptions of this device showed a simple board that could be held taut on a string in front of the eyes of the observer. 123 This is the simplest form of the kamal. In addition, James Prinsep explained the kamal which was used in the Maldives and Calicut. This kamal had nine knots on its string. It was the same instrument used for measuring the altitude of Pole Star. According to Prinsep, the unit of the isba was about 1°31’ to 1°36’ in modern measurements. This value corresponds quite well to the studies of Yen Dunjie.124

121 Arunachalam, B. 2002, p.48. 122 Arunachalam, B. 2002, p.43. 123 Arunachalam, B. 2002, p.46. 124 Arunachalam, B. 2002, p.46. ‐ 95 ‐

Moreover, the knots on this kamal also meant some particular harbor. The fourth, fifth, sixth, seventh, eighth, ninth and tenth knots each represented a specific harbor. 125 On the other side of the Indian Ocean, an officer of the Madras Artillery named Congreve described the native maritime traditions of the Coromandel Coast. This is the southeastern coastal region of the Indian Subcontinent, between the Eastern Ghats and the Bay of Bengal of the Indian Ocean. This stretch of coast was suitable for representation by knots on the string of the kamal. The knots of number represent the specific port latitudes. Sailors used these knots to identify the position of vessel.126 Actually, there were similar devices earlier in the twelfth century. They were called kau‐ velli‐palagai which meant “a board used to measure stars, held by teeth.” Another name was ra‐p‐palagai which meant “a board used during night.”127 Both of these boards were used by Tamil navigators and were made of rectangular boards from about 3 inches (7.6 cm) to 2 ¼ inches (5.7 cm). As with the Coromandel Coast kamal, specific knots represent the positions of specific ports.128

125 Arunachalam, B. 2002, p.46. 126 Arunachalam, B. 2002, p.46. 127 Arunachalam, B. 2002, p.48. 128 Arunachalam, B. 2002, p.48. ‐ 96 ‐

Figure 38: Map of East Coast of India. The line to the right shows how the ports were represented by knots on a string (B. Arunachalam, 2002, p.47).

B. Different sizes Chinese sources describe a slightly different version of this instrument:

蘇州馬懷德撁星板一副十二片，烏木為之，自小漸大。大者長七寸餘，標為 一指二指以至十二指，俱有細刻若分寸然。又有象牙一塊，長二尺，四角皆 缺，上有半指半角一角三角等字，顛倒相向，蓋周髀算尺也。129

129Li, Xu 李詡 1982, p.29. ‐ 97 ‐

Ma Huaide from Su Zhou said the Qianxing ban is a set of twelve boards, made of black wood and having different sizes. The biggest one was more than seven cun (寸)long; there were markings of zhi(指) units from one to twelve, and every board had clear scales. And there was also one board made of ivory two chi (尺)long, without the corners on the board. There were words such as half zhi, half jiao, one zhi, and three jiao, these words were upside down to each other; it was one kind of “Zhou Bi Shuan Chi”周 髀算尺.

This source shows that the qianxing ban was a set of boards, used together as a navigational instrument. It was composed of twelve boards of different sizes. To use the qianxing ban, one had to choose a board of suitable size to find the angle between the star and the horizon. This would have provided information for the travellers to determine the location of the ship in the ocean, perhaps after some calculations were performed. In his paper of 1966, Yan Dunjie discusses the unit of zhi (指). He mentions that one zhi is about 1° 36’ and had suggested that this instrument was borrowed from the Islamic countries and other nations sailing in the Indian Ocean, because they had similar instruments130. In Yan’s reconstruction, the qianxing ban was composed of twelve boards and one extra board without corners, as shown in figures 39 and 40.

Figure 39: Twelve boards from an illustruation by Yan Dunjie. (Yan Dunjie 嚴敦杰 1966, p. 77‐88).

130 Yan Dunjie 嚴敦杰 1966, p. 77‐88. ‐ 98 ‐

Figure 40: Multi‐purpose Board. From an illustruation by Yan Dunjie (Yan Dunjie 嚴敦杰 1966, p. 77‐88).

On the other hand, there were other types of boards, also arranged into sets. Sidi Ali was famous navigator who used the kamal on his voyages. His kamal was a set of nine boards and they measured a range of arcs in the sky from 4 to 12 isba.131 The Quanzhou Maritime Museum in China and the Maritime Experiential Museum in Singapore conserve these instruments.132 I learned that both of the sets of boards which compose a qianxin ban in China are reconstructions. Moreover, both of them are a set of twelve squares. In both of these devices, the squares of the set proceed from the largest to the smallest in an arithmetic progression. The instruments were not measured directly, but an estimation was made of the different width of each board. Due to the eyes parallax from windows, the measurements presented are not very precise. However, the estimates confirm the arithmetic progression from smallest to biggest. These estimates may be compared with the record of Li Xu from Song Dynasty, which states: The biggest one was more than seven (cun 寸) long A rule of thumb holds that in early China one cun varied between 2.31 and 2.43 cm today. According to the record of what I measured in Quanzhou, the biggest square was about 16.5 cm. Seven times the estimate (16.17 to 17.01 cm) is very close this material record. On the other hand, the set of twelve boards is identical with this source cited. For these reason, these

131 Arunachalam, B. 2002, p.51. 132 Thanks the Institute of History in National Tsing Hua University, Taiwan, for support in visiting these two museums. ‐ 99 ‐

reconstructed devices made the record by Li Xu as clear as day. However, the possibility remains that these devices were reconstructed on the strength of his description. Another qianxin ban conserved in Singapore also consists of a set of twelve boards. That may mean they also rely on the same sources written by Li Xu.

Table 5: Rough Measurements of the Qianxin Ban, from the Quanzhou Maritime Museum and the Maritime Experiental Museum in Singapore.

泉州海外交通史館 新加坡海事博物館

(Quanzhou Maritime Museum) (Maritime Experiential Museum) 1 16.5 cm 13.5 cm 2 15.5 cm 12.5 cm 3 13.5 cm 11.5 cm 4 12.5 cm 10.5 cm 5 11.5 cm 9.5 cm 6 10 cm 8.5 cm 7 9 cm 7.5 cm 8 7.7 cm 6.5 cm 9 6.7 cm 5.5 cm 10 5.7 cm 4.5 cm 11 4.7 cm 3.5 cm 12 3.7 cm 1 cm

Figure 41: Qianxin Ban. This photo was taken in the Quanzhou Maritime Museum in March, 2015. ‐ 100 ‐

Figure 42: Another Qianxin Ban. This photo was taken in the Quanzhou Maritime Museum in March, 2015.

Figure 43: Qianxin Ban. This photo was taken the in Maritime Experiential Museum, Singapore in March, 2015.

C. Different Sized Boards with Knots In Malayalam, there was a primary type of kamal called ra‐p‐palagai. This kind of instrument was developed on Chetlat Islands. Chetlat Islands is a coral island to the southwest of India. It belongs to the Lakshadweep Archipelago of India. In the coral islands, people

‐ 101 ‐

developed hand tools for navigation from turtle shell or some other shell artifact.133 They used the “kau” as a unit which had the same meaning as isba in Arabic: finger. This device had two boards, and it was originally constructed from two turtle shells. Among the ra‐p‐palagai instruments, there were different types. One may be traced from the Kavaratti Islands. Another was from Chetlat Island. Regardless of the source, they worked by the same simple principles and developed nearly simultaneously. The ra‐p‐palagai which was used on Kavaratti Island has two boards. One of the boards was 7.25.4 cm. The other was 3.62.7cm. The string of the bigger one had 8 knots and the string of the smaller one had 10 knots. This instrument was also for measuring the angle of stars and horizontal.

Conclusion Directional indicators, or compasses, can be sorted into two types: ones with magnetic needles and those without magnetic parts. Typically, Chinese compasses belong to the first type. These compasses have many direction marks around the outside and the lodestone rests in the middle of device. This indicator points out directions according to magnetic attraction. Chinese sailors used this instrument to understand directions. Meanwhile, navigators marked these directions on sea‐charts. Sailors collected this information over generations. Eventually, these experiences were gathered into a book, called Genlu Bu 更路簿 or Zhenlu Bu 針路簿. The second type of compass used stars to show the directions and can be called the “star compass”. The different bright stars which appeared in the evening told navigators the directions. Sailors could realize how long they had been sailing by the altitude of specific bright stars and when they passed the meridian. This kind of method worked with the zām, which was a unique time‐measurement on the Indian Ocean. This star compass not only could tell sailors direction but also could tell the direction of specific harbors. For example, navigators used a star compass centered on Socotra Island to recognize other harbors which lay in the Arabian Sea. After the success of the compass, another technologically advanced instrument is the astrolabe. This is a device can be traced from the Greek Age and developed from the ideas of

133 Arunachalam, B. 2002, p.50. ‐ 102 ‐

Ptolemy. The astrolabe was made according to different latitude and projected the stars onto a flat surface. In this way, observers could follow the movements of stars easily and understand time at same time. This device worked like a little computer to tell the day and time by stars. Most importantly, observers measured the angle between stars and horizon as a first step when they used it. There were also several kinds of langtian chi of different composures and formations. All of them were used to measure shadows. Because some scholars have suggested that qanxing ban originated from the Arab world, I have tried to find diagrams of Islamic navigation tools such as maps and astrolabes. For qanxin ban, there are three types. The first one has knots on the string line. Observers changed the distance between the board and their eyes according to these knots. By this method, the same board fit between the star and horizon but the length of the string changed. The second type was a set of different boards. Observers chose different size boards when the angle between the star and the horizon changed. The third type of qianxin ban had knots on the string and also different size boards. This type was normally used in Kavaratti Island which is Southwest from India in the Arabian Sea. All of these instruments above work with stars except the Chinese magnetic needle compass. They also existed in the several civilizations along this sea‐route. No matter whether the sailors used the star compass, an astrolabe, the qanxin ban, kamal, or the Kavaratti Island system, they all had a connection with observing stars. However, the Chinese magnetic needle compass relied on a lodestone to identify direction. It is hard to say that why Chinese developed differently and did not prefer instruments which worked with stars. In early ancient China, people still used stars such as Ursa Major to identify directions and locations. Even in this early period, though, it is hard to identify a Chinese method of measuring time analogous to the zām. Without this measurement method of zām, which accounted time by the movement of the stars, the time‐keeping of China developed from the sundial and references to the solar pathway. Moreover, water‐clocks such as The Ninth Centenary Su Song's Origination of Water‐powered Armillary Sphere (Shuiyun yixiang tai 水運儀象台) were used at nighttime to understand time‐ passing. Since time is important condition for navigation, especially for cross‐ocean voyages, the ‐ 103 ‐

different developments of time‐keeping influenced the maritime technology to develop in a different direction. For this reason, Chinese sailors used the more familiar Genlu to navigate, rather than the systems of other civilizations in which people used stars as guides. Moreover, this difference was also influenced the different instruments which developed in each culture.

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Zheng He

Introduction Zheng He led a great voyage in fifteenth century. This famous trip caused different cultures to communicate more deeply than before. For example, the products from different places could be exchanged and commerce was also developed. For this reason, foreign people became interested in porcelain from China and it became fashionable to use porcelain at home in some parts of the Muslim world. For similar reasons, people loved to use foreign fragrances as both medicine and a luxury product in China.134 Thus, to reconstruct Zheng He’s voyage, the background of these several expeditions must be explained. First, the people who worked with Zheng He must be introduced and the arrangement of the fleet of ships as they sailed must be described. Moreover, this sea‐route had been developed for several generations before Zheng He’s explorations. Thus, the development of this sea‐route had encouraged the growth of some harbors such as Quanzhou and Guanzhou in southeast of China. These places not only grew up as commercial centers but also became centers of cultural communication for topics such as religion. In addition, Zheng He was a Muslim and very possibly had strong connections with foreigners to make these voyages successfully. The success of Zheng He’s voyage represents the development of maritime technology sufficient to cross the open‐sea. The Qianwen Ji 前聞記 of Zhu Yuming 祝允明 (1460‐1526), records the seventh voyage of Zheng He and combines this data with the Treatise on Armament Technology. In this sea‐chart, there are at least two type navigation methods recorded. One used the magnetic needle compass and the other was guided by stars. Since there were different instruments, it also meant that they relied on different navigational theories. Due to this situation, the dates and details of Zheng He’s voyage from Qianwen Ji can be set out to explain how Zheng He successfully accomplished his voyage.

134 Kuwahara Jitsuzo 桑原騭藏 , 1971, p.41. ‐ 105 ‐

Since there are so many cultures on this sea‐route and the maritime technology knowledge changed with each culture, it is easier find the method of navigation from the instruments mentioned and the linguistic connections with the names used in the navigation methods. Thus, part of the evidence explains how maritime knowledge spread in different civilizations by people’s voyages on this sea‐route. Moreover, historical events can happen quickly but often build on potential issues which have been developing for a long time. In the same way, these maritime devices such as astrolabe or qianxin ban might appear suddently but depended on knowledge which evolved over a long time. No one could have invented them suddenly without the technological knowledge behind them. For instance, the astrolabe, the quadrant, the sextant and qianxin ban embodied similar astronomical theories and depended on the technique of stereographic projection to varying degrees. Thus, since these above conditions had been satisfied for Zheng He’s voyage, this era was a brilliant age which could realize the promise of these techniques. The mature maritime knowledge influenced cultural communication. On the other hand, though, the greater cultural interaction helped the finanical development and attracted more people to do business and push maritime technology even further. The result was an Age of Discovery.

Background The famous explorer Zheng He conducted several maritime expeditions even as far as the Persian Gulf and the Horn of Africa. For these explorations of Zheng He, each voyage needed a structured system. Thus, the command structure consisted of five parts. The first were the “leaders,” people such as Zheng He, Wang, Jinghong, Li Xing 李興, Hong Bao 洪保. They made policy decisions and executive orders for the whole voyage, including the diplomatic communications. The second were the people familiar with maritime technology. These people, who had been sailors, were called huo zhang 火長 helped the whole fleet of ships to sail successfully. In addition, the yinyang guan 陰陽官 (a type of astronomer) were in charge of astronomical and weather predictions. This technological group also included ship‐builders, sailors, and oarsman. Thirdly, the translators were responsible for the diplomatic etiquette and ‐ 106 ‐

translations. Fourth, the accountants, doctors, and couriers were responsible for monetary accounts, protect public health, communicating with supply boats, and receiving commendations from the Ming government. Fifth, common soldiers protected ships from being attacked by pirates.135 In additions, during Zheng He’s voyages, there were at least five types of ships. Firstly, the flagship where the first group of people stayed, was called bao chuan 寶船 (treasure boats). The second was the ma chuan 馬船 (horse boats), which were the fastest sailing among these five sorts of boats. The second type of boat was responsible for fighting and communication. The third was liang chuan 糧船 (grain boat) and it stored food and supplied all of the other boats. Fourth was the zuo chuan 坐船 (seating boat), the type of ship in which most of the sailors stayed. The fifth type of ship was zhan chuan 戰船 (war boat), which sailed outside of the fleet of ships and protected the whole fleet. Moreover, there were several little boats which were used to navigate the shallow waters of harbors.136 However, when we try to trace the route of Zheng He, the sea‐route resembles other voyages from before the age of Zheng He: specifically, 從公元二世紀開始，不斷駛船越過印 度洋進入南海…137(From the beginning of the second century AD, sailing boats continuously crossed from the Indian Ocean to the South China Sea...). Long before the Hijira of Mohammed (622 AD) inspired Muslim missionaries to travel east, the monk Faxian 法顯 (337‐422 AD) traveled southeast Asia in service to Buddhism. Although Faxian travelled by foot from China to India, he opted to take a boat back from India. Faxian was not a navigator but he recorded his experiences of navigating by reference to the stars. 師子國....東行二日，便值大風，晝夜十三日，到一島邊，補塞船漏，於是復前，凡九 十日許，乃到一國，名耶婆提，其國外道婆羅門興盛，佛法不足，言停此五月日，復 隨他商上船，以四月十六日發，東北行去廣州...138 Sri Lanka was two days travel to the east. Then, there was a strong wind for thirteen days and nights. We arrived at an island and beached the boat as before. After ninety days, we arrived in a country called Ye po ti 耶婆提 (Sumatra). In this country waidao poluomen 外道 婆羅門 the foreign religion of Brahmanism was popular, and Buddhism was not known. I stayed here five months and departed with a trader, who departed on the sixteenth day of the fourth month, heading northeast to Gunagzou.

135 Sun, Kungqi 孫光圻, 1993, p.223. 136 Sun, Kungqi 孫光圻, 1993, p.225. 137 Huang, Qichen 黃啟臣, 2003, p.50. 138 Ding, Qian 丁謙, 1971, p.10B. ‐ 107 ‐

Although Faxian was a religious scholar and not an astronomer, his account makes clear that while travelling by boat, the stars were an indispensable reference for navigation.

Figure 44: Voyage of Faxian. Note that he sailed on the open ocean (Huang Qichen 黃啟臣, 2003, p.82).

Faxian travelled in search of classical books on Buddhism. During his life, missionaries spread Buddhism throughout Asia. However, in his travels, Faxian also encounted countries which had met Brahman missionaries. The presence of Brahmanism indicates that the Faxian used sea routes which had existed for a long time. Faxian described these sea routes by reporting locations and the number of days travel which separated them. By the time of Zheng He, Arabs followed the same sea routes and the reports of Zheng He’s voyage even described the sea routes in the same way. Thus, sea routes have connected ancient China with western countries for a long time. The sea‐routes between the east and west may be collected into a single map. Different colors illustrate the changes which had take place in these paths during the long history of navigation. Here, green marks the paths of the Han Dynasty; blue shows the routes of the Song Dynasty; purple represents the Yuan Dynasty; and red outlines the most recent sea‐route of Zheng He in the Ming Dynasty. Even from early times in the Han Dynasty, sailors travelled on long voyages in the open ocean. ‐ 108 ‐

Figure 45: Sea Routes of Different Dynasties (Huang Qichen 黃啟臣, 2003, p.53,130,263,340,370)

Until the Tong Dynasty, the most popular sea‐route may be described as a set of general directions. 沿著傳統的南海海路，穿越南海、馬六甲海峽，進入印度洋、波斯灣，在烏刺國， 如果沿波斯灣西海岸航行，出霍爾木茲海峽後，可進入阿曼灣、亞丁灣和東非海岸， 歷經九十餘個國家和地區，航期八十九天…139 To follow the traditional sea‐route of the South China Sea, go through the South China Sea, and the Malacca Strait to enter the Indian Ocean and the Persian Gulf, arriving at the country of Wuci; if the west‐coast of the Persian Gulf is followed, then after leaving the Straight of Hormuz, enter the Oman Bay, Aden Bay, and the coastline of east Africa, passing ninty more countries and areas in eighty‐nine days. By the end of the Tang Dynasty, this sea‐route had been developed very well. Most importantly, this sea route was already a mature, commercial pathway. Many merchants sold their wares from different countries. 武后時，雖有泉州，而據高僧傳中國僧往印度及印度僧來中國，無一經過泉州。可 知即當盛唐之時泉州仍未興旺。新唐書地理志泉州下特注往琉球等國所需數日，唐 末似已成為商港，惟不著廣州之盛耳。五代時，閩王王審知施政政策之一，為招來 海中蠻夷商賈，是由番商大至，至北宋時，市乃繁昌，…泉州與廣州並列矣。140 In the reign of Empeor Wu Hou, Quanzhou had a harbor but according to the Book of Gaoceng, whenever Chinese or Indian Buddhists came to China, none of them came via Quanzhou. Thus, we know Quanzhou not popular until Tang Dynasty. From the “Geography” of History of New Tang Dynasty, it was necessary to travel several days from Quanzhou to Ryukyu. It seems that it had become a popular business harbor in the Tang Dynasty, but it was still not as popular as Guanhou. In the Wu Dynasty, one of the kings of

139 Huang, Qichen 黃啟臣, 2003, p.128. 140 Zhang, xinlang 張星烺, 1931, p33‐39. ‐ 109 ‐

Ming established a rule to attract foreign businessmen, until by the North Song Dynasty, it have become as popular as Guangzhou. According to this source, Quanzhou 泉州 had been developed as early as the Tong Dynasty. Especially during the Wu Dynasty (907‐960), though, the Chinese government encouraged foreign merchants to settle in Quanzhou to conduct commercial activities. Thus, Quanzhou was becoming more important harbor throughout the Song and Yuan Dynasties. Due to this commercial development, Quanzhou attracted many foreign merchants. As the citation below indicates, the Chinese government had made rules to standardize the mercantile activities, including taxes. 徽宗正和六年二月二十二日，詔今後蕃夷人入貢並選差承物即以上清疆宮押伴依行 程，無故不得過一日，因而乞取置買，以自盜論，福建路市舶司上言，大食蕃國蒲 囉辛造船一隻般載乳香，泉州市舶計抽解價錢三十萬貫，委是勤勞，理當優異。141 On the twenty‐second day of the second month in the sixth year of the Huizong Empire, it was announced from the Qingqian Palace that goods from foreign merchants and those in the charge of designated recipients cannot remain for more than one day; if delivery is taken later and the goods are sold, it will be accounted as theft. A reply came from Shiboci Harbor in Fujian province: the Puluoxin family from Arabia had built a boat and frequently loaded it, it was accounted as three hundred thousand quan by Shiboci Harbor in Quanzhou, so it follows that hard work was unsurprisingly advantageous. At that time, the South Song Dynasty encouraged foreign commerce to solve financial issues. For this reason, Quanzhou became an important place.142 Moreover, Chinese merchants sold gold, silver, porcelain, tea and silk. Other goods, such as fragrances, seasonings, medicines, jewels, and ivory came into Quanzhou from other countries and could be bought at competitive prices. For this reason, archaeological studies often find ancient coins of Song Dynasty in Middle East countries. Discoveries of this material trace the pathways of this prosperous sea‐route.143 In the lands to the west of India, though, Arabic astronomy, was essential to navigation. While some of the techniques of navigation may have passed unrecorded, Arabic astronomy made clear the paths of technical communication. Arabic technology, especially astronomy, was

141 Xu, Cong 徐松, 1957, p.7760. 142Zhang xinlang 張星烺.1931, p33‐39. 143 Kuwahara Jitsuzo 桑原騭藏, 1971, p.41. ……南渡後，經費困乏，一切倚辦海舶。歲入固不少，然金銀銅錫 錢幣亦用是漏泄外境，而錢之泄尤甚。法禁雖嚴，奸巧愈密其弊卒不可言。……考察宋代外國貿易之實際情 形，知當時由中國輸出海外之物，以金銀銅錢絹瓷器為主，而由海外輸入中國之物，則以香料、藥、珠玉、 象牙、犀角等為主 After the North Song Dynasty, the finacial situation was poor,and entirely dependant on foreign import. Although the income was very good, gold, silver, bronze, and tin were still expensive, especially as coins. Although the rules were very strict, corruption inceased; studies on the commerical stiaution of the Song Dynasy find that the Chinese exported gold, silver, bronze,silk and porcelian, and imported goods, like fragrances, medicines, jewels, ivory,and rhinoceros horn. ‐ 110 ‐

important even in China during the Song Dynasty (920A.D.‐1279A.D.) Because Quanzhuo was one of the largest ports in the world, China encountered many foreigners and most of them were Muslim. The History of Yuan (元史), among other Chinese sources, records why these Muslims came to Quanzhuo and why they stayed there:互市之法，自漢通南粵始，其後歷代 皆嘗行之，至宋置市舶司於浙、廣之地，以通番貨易，則其制為益詳矣。144 (The law of intercity trade, was established from the Han Dynasty through the Southern Guangdong. Then each dynasty thereafter tried its conduct. The Song Dynasty founded the Maritime Trade Superintendency and also the Superintendency of the Canton at Zhejiang, so that foreign goods might pass easily. The details of this beneficial system have been carried on [to the present day].) Because the law of intercity trade permitted foreign goods to pass easily in the Song Dynasty, Quanzhuo became the site of exchange between Chinese and foreign merchants. Quanzhuo attracted Chinese traders who sold native products such as porcelain, gold, and tea. Quanzhuo also welcomed Western traders who brought spices, ivory, jewels, medicine, and other trade goods.145 In this way, Quanzhuo developed into a huge market for many types of businesses. With this economic activity came the government institutions which regulated financial issues. It attracted foreigners for business, but what kind of knowledge guided these merchants to the Far East in order to do business? Chinese primary sources offer few motivations for foreign people, but some answers may be found from foreign sources. Clearly, Quanzhou attracted foreigners, but the knowledge which guided them to the port originated elsewhere. Because navigation is a practical art, intended to be practiced by sailors rather than discussed by intellectuals, more information was communicated orally than in writing. Unreliable methods and out‐moded techniques would have disappeared quickly from the historical record. A historical hypothesis may be adopted: the art of navigation circulated at least as well as the science of astronomy. The two fields are related, but whereas astronomy represented the intellectual peaks of astronomical endeavors, navigation accounted for the basic practices.

144 Sung Lian 宋濂, 1997, p.625. 145 Kuwahara Jitsuzo 桑原騭藏 , 1971, p.41 ‐ 111 ‐

Arabs were very familiar with Greek astronomical works. Arabs knew the works of Ptolemy well in Middle Ages. Arabs had translated the Geography of Ptolemy and the works of other Greek geographers.

How did Zheng He Succeed in His Voyage? Zheng He led seven expeditions, however, not every voyage sailed as far as Hormuz. Qianwen Ji records the exact dates of the seventh voyage of Zheng He. Thus, the table lists the date of the stages in the voyage of Zheng He. Each stage has a number, and it is also contains the Chinese date, the conversion of that date into a Western date, the location where Zheng He arrived, and some events of Zheng He. Then, for each number, a mark is placed on the map below. Together with the table, this map describes Zheng He’s voyage. The steps of how Zheng He sailed are combined with the number. For this reason, it is easier to compare with the modern places. Some places, such as number twenty‐six and twenty‐seven, are hard to identify the precisely. However, even though these two places are not recognized today, Zheng He’s whole voyage may still be understood clearly.

Table 6: Qianwen Ji and the Western Date by Hsu Sheng‐I 徐勝一 and Chan Yau‐Zhih 陳有志.

No. Chinese Date Western Date Location Event 宣德五年 (1431) 1 1431.01.19 Long Bay 龍灣 Departure 閏十二月六日 宣德五年 2 1431.01.23 Mt. Xue 徐山 閏十二月十日 宣德五年 3 1431.02..02 Fuzimen 附子門 閏十二月二十日 宣德五年 4 1431.02.03 Liujia Harbor 劉家港 閏十二月二十一日 宣德六年 (1431) 5 1431.04.08 Changle Harbor 長樂港 二月二十六日 宣德六年 6 1431.12.16 Mt. Fudou 福斗山 十一月十二日 宣德六年 7 1432.01.12 Wuhumen 五虎門 十二月九日 ‐ 112 ‐

宣德六年 8 1432.01.27 Champa 占城 十二月二十四日 宣德七年 (1432) Departure from Champa 1432.02.12 正月十一日 從占城出發 宣德七年 9 1432.03.07 Java 爪哇 二月六日 宣德七年 Departure from Java 1432.07.13 六月十六日 從爪哇出發 宣德七年 Sambojia Kimdom 10 1432.07.27 六月二十七日 (Jiu Harbor 舊港) Departure from 宣德七年 1432.07.27 Sambojia Kimdom 七月一日 從舊港出發 宣德七年 11 1432.09.02 Sumatra 蘇門答刺 七月八日 宣德七年 Departure from Sumatra 1432.11.02 十月十日 從蘇門答刺出發 宣德七年 12 1432.11.28 Ceylon 錫蘭山 十一月六日 宣德七年 Departure from Ceylon 1432.12.02 十一月十日 從錫蘭山出發 宣德七年 Calicut/Kozhikode 13 1432.12.10 十一月十八日 古里國 宣德七年 Departed from Calicut 1432.12.14 十一月二十二日 從古里出發 宣德七年 14 1433.01.17 Hormuz 魯乙忽模斯 十二月二十六日

宣德八年 (1433) Return from Hormuz 15 1433.03.09 二月十八日 從魯乙忽模斯回洋 宣德八年 Calicut/Kozhikode 16 1433.03.31 三月十一日 古里國 宣德八年 Departure from Calicu 1433.04.09 三月二十日 從古里出發 宣德八年 17 1433.04.25 Sumatra 蘇門答刺 四月六日 宣德八年 Departure from Sumatra 1433.05.01 四月十二日 從蘇門答刺出發 ‐ 113 ‐

宣德八年 18 1433.05.09 Malacca 滿刺加 四月二十日 Return to Quanlun 宣德八年 19 1433.05.27 Ocean 五月十日 回到崑崙洋 宣德八年 20 1433.06.09 Chikan 赤坎 五月二十三日 宣德八年 21 1433.06.13 Champa 占城 五月二十六日 宣德八年 Departure from Champa 1433.06.17 六月一日 從占城出發 宣德八年 22 1433.06.19 Mt. Wailuo 外羅山 六月三日 宣德八年 23 1433.06.25 Mt. Nanao 南澳山 六月九日 宣德八年 Saw Mt.Wanglanghui 24 1433.06.26 六月十日 看到 望郎回山 宣德八年 25 1433.06.30 Qitou Ocean 琦頭洋 六月十四日 宣德八年 26 1433.07.01 Wandie yu 碗碟嶼 六月十五日 宣德八年 Via Daxiaochi 過大小 27 1433.07.06 六月二十日 赤 宣德八年 Entered Taicang Port 28 1433.07.07 六月二十一日 進太倉 宣德八年 29 1433.07.22 Arrived at capital 到京 七月六日 Grant of honors and 宣德八年 1433.07.27 award 七月十一日 關賜獎衣寶鈔

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Figure 46: Sea‐route of Zheng He. The numbers indicate the locations tabulated in the preceeding table and represent the steps of Zheng He’s voyage (Zhu Yuming, Qianwen ji, 1966).

In the time of Zheng He, there was an official shipyard named the Longjiang Shipyard (Longjiang chuanchang 龍江船廠,) in a suburb of modern Nanjing 南京. It was an important shipyard for building the baochuan which Zheng He took for his voyage. Before the first step of Zheng He’s departure, the most important condition was the presence of the monsoon wind. The monsoon is the key point of navigation. Tracing Zheng He’s voyage shows that they followed a rule: they departed in the winter and came back in the summer.146 For this reason, the departure date of Zheng He was the nineteenth of January in 1431. These facts indicate that Zheng He’s voyage departed in winter and follow the northern monsoon from Siberia. 147 Thus, after sailing out of the harbor, the sailors used the method of navigating by the magnetic needle to sail. Sailors used the magnetic needle compass to identify direction. In addition, they accounted time in units of gen (更, an ancient unit of time at night) to realize how

146 Zhu Yuming 祝允明, 1966, p.37A‐38A. 147 The wind blows from the north of central China in winter and Nanjing belongs to this area. ‐ 115 ‐

long they had been sailing. For the stages of the voyage numbered one to eleven, that is, the portion of the sea‐route until Sumatra, the sailors used the traditional Chinese method of navigation. This method also corresponds with the Treatise on Armament Technology, which points out place number four, Changle Harbor 長樂港. This magnetic needle information continues until Longxian yu (龍涎嶼, Breueh/Bras)148 which is an island near modern Sumatra. The two diagrams below are from the Treatise on Armament Technology. The figure 47 shows the area near Sumatra and contains a lot of information about the magnetic‐needle route. The direction of the magnetic‐needle route is recorded on these dotted lines. In addition, the figure 47 near the Ceylon diagram reports the term zhi next to the dotted lines after certain digits, indicating that it is a navigational unit.149 This change in notation represents that sailors started to use another navigation method which relied on stars.

Figure47: Sea‐route from Stage 11 to 12 (see Table 6). The area titled A is outlined in red. The area called B, is outlined in blue.

The figure above shows the route from Sumatra to Ceylon, which are numbered eleven and twelve, respectively. This route represents a part of the ocean in which sailors had to sail across the open‐sea to arrive at the place of their goal. Again, the monsoon helped sailors in their directions, too. For this sea route, they used the northeast wind to depart from Sumatra and sail to Ceylon in winter. Later, in the summer, they used the southwest wind to sail back

148 Chen Guifang, Xiefang 陳桂榮, 謝方, 1985, p.256. 149 The charts are named “Zheng He’s Sea‐Chart from Nanjing to Foreign Countries” (zi baochuan chang kaichuan chang cong longjiang guan chu shui zhida waiguo zhufan tu 自寶船廠開船從龍江關出水直抵外國諸番圖). ‐ 116 ‐

from Ceylon to Sumatra. Sailors relied on the northeast wind in winter which is confirmed by the day of departure (1432.11.02) from Sumatra. For this portion of the voyage, sailors used the “star compass” to identify direction. They usually observed the bright stars at dusk and counted by the zām method to measure time. Sailors relied on the lunar mansions to find the dates of month and predict the rise and fall of tides. These lunar mansions can work with zām to measure time. Moreover, since identifying the position of the stars became an important condition for sailing, the fettering method was the original way to remember the relative position of stars, especially on cloudy days. On the other hand, to help sailors keep on the same latitude and avoid getting lost, the qiyas method was the first choice of method. By this method, the sailors measured the angle of Pole Star from the horizon with a specific instrument which was named qianxin ban or kamal. Then, the unit of angle was found in isba which could also be used with zām. Sailors measured the change of the angle and converted into zām to understand how long it had been. The Treatise on Armament Technology also includes a set of four diagrams entitled the Chart of Sea‐ Crossing by Fettering Stars. This chart shows how constellations could have guided Zheng He’s fleet from Sumatra to Sri Lanka and from Calicut to Hormuz.150 Hsu Sheng‐I 徐勝一 and Chan Yau‐Zhih 陳有志 tried to sort out the constellations in these diagrams with respect to the modern western names. Thanks to this study, the dates and locations of Zheng He’s voyage can reveal what stars Zheng He chose for navigation.151 According to these studies, the stars of the “Chart of Sea‐Crossing by Fettering Stars” can be tabulated and used to reconstruct Zheng He’s decisions on the voyage. A modern explanation of Zheng He’s choices should refer to the modern constellations. This explanation is based in a translation of the descriptions which appear in the “Chart of Sea‐Crossing by Fettering Stars.” In this way, the night sky of Zheng He’s voyage can be reconsidered.

150 Mao Yuanyi 茅元儀 1621 , pp.319. 151 Hsu Sheng‐I, Chan Yau‐Zhih, 徐勝一, 陳有志, 2008, p.103‐104. ‐ 117 ‐

Table 7: Translation of Star Names from the “Chart of Sea‐Crossing by Fettering Stars” (Hsu Sheng‐I, Chan Yau‐Zhih, 徐勝一, 陳有志, 2008, p.103‐104).

Chinese Star Names Western Stars Names Beichen xing 北辰星 α Ursae Minoris / Polaris Huagai xing 華蓋星 Cassiopeia Zhinu xing 織女星 α Lyrae / Vega Beibusi xing 北布司星 β Geminorum / Pollux α Canis Minoris / Nanbusi xing 南布司星 Procyon Seven stars in the west 西邊七星 ηTaurus / Pleiades Denglonggu xing 燈籠骨星 Crux / Southern Cross one of Nanmen shuang xing 南門雙星之一 β Centauri / Hadar another of Nanmen shuang xing 南門雙星之二 α Centauri / Rigil Kent Shuiping xing 水平星 α Carinae / Canopus

Figure 48: “Chart of Sea‐Crossing by Fettering Stars” from Lungxian yu 龍涎嶼 to Ceylon (Hsu Sheng‐I, Chan Yau‐ Zhih, 徐勝一, 陳有志, 2008, p.103‐104). ‐ 118 ‐

龍涎嶼往錫蘭過洋牽星圖: 看東西南北高低遠近四面星，收錫蘭山。時月往忽魯、別 羅里。開洋牽北斗雙星三指，看西南邊水平星五指一角，正路看東南邊燈籠骨星下雙

星平七指，正路看西邊七星五指半平。 The Chart of Sea‐Crossing by Fettering Stars from Lungxian yu 龍涎嶼 to Ceylon: observing the east, west, south, north, from high to low and far to close until Ceylon. Time to Hormuz and Beiluoli 別羅里 (Beruwala). Start sailing and fetter Ursa Minor to three zhi, observing Canopus at five zhi and a jiao in southwest, the correct route shows the Southern Cross and Centaurus equal to seven zhi, the correct route shows the Pleiades equal to five zhi and a half. The diagram also preserves several annotations of constellations. These annotations and the associated constellations are labelled A through E. A. 北斗頭雙星平三指，一角平水。B. 北辰星第一小星平三指一角平水。C. 西邊七星 五指半平水。D. 西南水平星五指一角平水。E. 燈籠星七指平水。 A. The first double star of Ursa Major equals three zhi, one jiao equals the horizon. B. The first star of Ursa Minor equals three zhi, one jiao equals the horizon. C. In the West, the Pleiades equal five and half chi with the horizon. D. In the southwest, Canopus equals five zhi and one jiao with the horizon. E. The Southern Cross equals seven zhi with horizon. In the case of A, Hsu Sheng‐I and Chan Yau‐Zhih have noted some difficulty with the identification of the constellation.152 In addition, between the stations numbered twelve and thirteen, the vessel gets close to the coastline again. The culturally distinct Tamil people occupy south India. They also had a similar instrument called kau‐velli‐palagai which meant “a board used to measure stars, held by teeth” in Tamil. On the other shores lived the Malayalam people of southwest India. They also had similar device of shells and tied with knots to measure the stars altitude. Both Tamil and Malayalam belong to the Dravidian language family. As understood in this culture, the navigation instruments were composed of knots. It not only told information for sailors about

152 Hsu Sheng‐I, Chan Yau‐Zhih, 徐勝一, 陳有志, 2008, p.103‐104. ‐ 119 ‐

angles, but they also represented specific harbors on the Indian peninsula. Calicut was one of the important harbors at that time. However, according to the sea‐chart from the Treatise on Armament Technology, the magnetic‐needle route reappeared again when the sea route drew close to land. Moreover, the multiple angular units, such as zhi (isba), were marked together. This double entry system proves that this sea‐chart was drawn by Chinese navigation methods but also recorded others civilization’s navigation methods at the same time. These notes are evidence of the communication of culture (as shown by the measuring units) and knowledge (as indicated by the values of the coordinates).

Figure 49: Detail of Sea‐route. The highlighted text reads 用庚丙針四十五更；華蓋七指二角 (Use the needle with geng bing and fourty‐five gen；Huagai is at seven zhi and two jiao. (Mao Yuanyi 茅元儀 the Treatise on Armament Technology, 1984.)

When Zheng He made his voyage from Calicut to Hormuz (number thirteen to fourteen on his map), he encountered the winter monsoon. This monsoon began in October and blew from India. Zheng He departed from Calicut on tenth of December, 1432, which corresponded with the height of the monsoon season. Because the fleet had to cross the Arabian Sea, the observation of stars’ altitudes became necessary again. In the same journey from Sumatra to ‐ 120 ‐

Ceylon, they used zām and stars to identify the time, the direction, and arrival at the goal, Hormuz. Moreover, the record from the Treatise on Armament Technology, started to present lots of units of stars’ altitude and wrote more descriptions with zhi on the dotted line which represent the course of the vessel.

Figure 50: Chart of Sea‐Crossing by Fettering Stars from Calicut to Hormuz (Hsu Sheng‐I, Chan Yau‐Zhih, 徐勝一, 陳 有志, 2008, p.103‐104).

古里國往忽魯謨斯過洋牽星圖：○○指過洋，看北辰星十一指，燈籠骨星四指半，看 東邊織女星七指為母，看西南布司星九指，看西北布司星十一指。丁得把昔開到忽 魯模斯，看北辰星十四指。 The Chart of Sea‐Crossing by Fettering Stars from Calicut to Hormuz: OO zhi for sea‐ crossing, observe Ursa Minor at eleven zhi, Southern Cross at four and a half zhi, observe Vega at seven zhi as the standard in the east, observe Canis Minor at eleven zhi. From Dingdebaxi to Hormuz, observe Ursa Minor at fourteen zhi.

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F. 丁得把昔過洋牽北辰星七指平水。G. 到沙姑馬山看北辰星十四指平水。H. 西北 布司星十一指平水。I. 西南布司星九指平水。J. 到沙姑馬山燈籠骨星四指半平水。K. 丁得把昔過洋燈籠骨星八指半平水。L. 南門雙星六指平水。M. 東邊織女星七指平 水 。 F.Sea‐crossing at Dingdebaxi fetter Ursa Minor at seven zhi from the horizon. G. Observe Ursa Minor at fourteen zhi from the horizon at Mt. Saguma. H. Keep Canis Minor at eleven zhi from the horizon in the northwest. I.Keep Canis Minor at nine zhi from the horizon in the outhwest. J.( Arrive at Mt. Saguma, fit the Southern Cross at four zhi from the horizon. K. Sea‐Crossing at Dindebaxi to fit Southern Cross at eight and half zhi from the horizon. L. Keep α, β Centauri at six zhi from the horizon. M. Keep Vega at seven zhi from the horizon in the east.

Figure 51: Portion of Sea‐route near Stage 14, Hormuz (see table 6). The area named A, is outlined in rectangle and contains the text, 佐法兒北辰八指、The area called B, shows genlu information with a dotted line (Mao Yuanyi, 茅元儀, Treatise on Armament Technology, 1984.)

Zheng He started his return voyage from Hormuz on the ninth of March in 1433. This return also correspond the southeastern monsoon which began in March on the eastern shores of Africa in Arabian Sea. After having sailed for twenty‐two days, Zheng He’s reliance on this wind was rewarded with his arrival in Calicut. They took advantage of the monsoon and departed from Calicut back to Sumatra and arrived there on the twenty‐fifth of April in 1433. ‐ 122 ‐

Again, these dates match the dates of the monsoon which normally blew eastward until June. During this time, they also used stars as guides for understanding the time in terms of zām.

Figure 52: Chart of Sea‐Crossing by Fettering Stars from Hormuz to Calicut (Hsu Sheng‐I, Chan Yau‐Zhih, 徐勝一, 陳 有志, 2008, p.103‐104).

忽魯模斯回古里國過洋牽星圖: 忽魯模斯回來，沙姑馬開洋，看北辰星十一指，看 東邊織女星七指為母，看西南部司星八指半。丁得把昔看北辰星七指，看東邊織女 星七指為母，看西北布司星八指。 The Chart of Sea‐Crossing by Fettering Stars from Hormuz to Calicut: back from Hormuz, departing from Saguma, observe Ursa Minor at eleven zhi, observe Vega at seven zhi as the standard in the east, observing Canis Minor at eight and a half zhi. Observe Ursa Minor at seven zhi in Dingdebaxi, observe Vega at seven zhi as the standard in the east, observe β Geminorum at eight zhi in the northwest.

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N. 沙姑馬山開洋，看北辰星十一指平水。丁得把昔過洋，看北辰星七指平水。O. 北辰星十一指平水。P. 西北布司星八指平水。Q. 西南布司星九指平水。R. 骨星八 指半平水。S. 東邊織女星七指平水。 N. Departure from Mt. Saguma, observe Ursa Minor at eleven zhi from the horizon. Sea‐ Crossing at Dindebaxi, observe Ursa Minor at seven zhi from the horizon. O. Keep Ursa Minor eleven zhi from the horizon. P. In the west, keep β Geminorum at eight zhi from the horizon. Q. In the west, keep Canis Minor at nine zhi from the horizon. R. Keep the Southern Cross at eight and half zhi from the horizon. S. Keep Vega at seven zhi from the horizon.

Figure 53: Chart of Sea‐Crossing by Fettering Stars from Ceylon to Sumatra (Hsu Sheng‐I, Chan Yau‐Zhih, 徐勝一, 陳 有志, 2008, p.103‐104).

錫蘭山回蘇門答剌過洋牽星圖: 時月正回南巫里洋，牽華蓋星八指，北辰星一指， 燈籠骨星十四指半，南門雙星十五指，西北布司星四指為母，東北織女星十一指平 兒山。

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The Chart of Sea‐Crossing by Fettering Stars from Ceylon to Sumatra: time to return from the Nanwuli Ocean, fettering Cassiopeia at eight zhi, Ursa Minor at one zhi, the Southern Cross at fourteen and a half zhi, and α, β Centauri at fifteen zhi, use β Geminorum at four zhi as the standard in the northwest on Mt. Pinger. T. 華蓋星八指平水。U. 北辰星一指平水。V. 西北布司星四指平水。W. 西南布司星 四指平水。X. 燈籠骨星正十四指半平水。Y. 南門雙星平十五指平水。Z. 東北織女星 十一指平水。 T. Keep Cassiopeia at eight zhi from the horizon. U. Keep Ursa Minor at one zhi from the horizon. V. In the northwest, keep β Geminorum at four zhi from the horizon. W. In the southwest, keep Canis Minor at four zhi from the horizon. X. Keep the Southern Cross right at fourteen zhi from the horizon. Y. Keep α,β Centauri at fifteen zhi from the horizon. Z. In the northeast, keep Vega at eleven zhi from the horizon. After his arrival on Sumatra, Zheng He started sailing in the Quanlun Sea 崑崙洋 which is the open sea southeast of modern Vietnam. Thus, sailors followed the southwest monsoon and used the magnetic‐needle route to navigate the coastline of Vietnam and southeast of China on their journey back to Nanjing.

Linguistic Connections In Chinese, the word zhi 指 means finger. In this way, this word has the same meaning as isba in Arabic. The similarity of the meaning of these two words and the similarity of their navigational use suggests that a linguistic borrowing occured between Chinese and Arabic. Among linguistic borrowings, there are three primary categories. The first type, a loanword, keeps the sound. Normally, this category is used for names, like Aristotle 亞里斯多德. The second category, a calque, preserves the meaning of the borrowed word. For example, when the world “telescope” is rendered in Chinese as 望遠鏡. 望 preserves the meaning of “look” from the Greek “σκοπεῖν” (to see) and 遠 corresponds to the adverb “τηλοῦ ” (at a distance). The third category, called loan blends, imitates both the sound and meaning of the donor language. For example, the Chinese term for “talk show” is 脫口秀, which may be transliterated as tuōkǒu xiù, and translated literally as “escape‐the‐mouth show” (xiù itself is a loanword).

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Apparently, the Chinese zhi is a calque of the Arabic isba. Both words mean finger, but the direction of this borrowing must be established with reference to historical and technical context. The name of the instrument qianxin ban describes the use of the board in the “fettering” of a heavenly arc. Because the instrument was a board, it was considered a type of ban; because it was used with stars, the noun xin was included in its name. The practice of what was done with in Arabic which ( كمال) those stars was “qian” and this word seems to be a calque of kamal (کمان) means “arc” or “bow”. This word developed as a loanword from the Persian word kamān which means “arc,” too.153 Moreover, the Tamil word contains many of the same elements as the Chinese phrapse. They called the same board kau‐velli palagai in the Tamil language. Here, kau means “to catch by mouth,” while velli literally means “silver” but has been used in reference to the color of the stars. Finally, palagai is a type of board. This term seems to derive from a description of the practice of holding the string between the teeth. Likewise, the Malay called the same board Ra‐p‐palagai in Malayalam, meaning a board used during night. Not only the instruments but also the units of measure on this device were linguistic borrowings between different cultures. Compared with the name of the device name, the basic meaning of word is simpler than the name of the tool: it simply means finger. Thus, according to this statement, there is the table for the word meaning finger in different cultures. In all cases, this word is a calque, but it is used for units of measure.

Table 8: The word “finger” in different languages.

South coast Chinese Arabic Gujarat of India

viral dhru (إصبع) Finger zhi (指) isba

In contrast to the fact that the units are all calques, the zām which indicate the sailing distance and time enters other languages as a loanword. It was called zāma in Sanskrit, yamam

153 Arunachalam, B. 2002, p.48. The root of this word is “qaws”. ‐ 126 ‐

in Tamil, and dama in Maldivian.154 Moreover, it was also know for several term such as wam, bam, tan, bagam, maaru in Indian dialects.155 In short, the linguistic phenomena above, no matter what category of linguistic borrowing the represent, explain the same things. These terms include measurement methods, particulary devices and units which existed in several civilizations on Indian Ocean. It also suggests that this maritime knowledge was transmitted among cultures with the development of the sea‐route in the Indian Ocean.

Development of Instruments Instruments developed differently with time and with different people. In the Age of Discovery, especially since late fifteenth century, these instruments represent the maturation of maritime technology. In this situation, some clues about the developmental path of the instruments can be sorted out. The main function of astrolabe was to measure the distance of heavenly bodies from the horizon to determine the time by rotating the middle. However, these measurements could be made without rotating around a full circle. Thus, for this reason, the quadrant became the important part for measuring. Due to this, the quadrant had been developed into an independent, simplified maritime instrument for a long time. Moreover, each instrument developed from a previous, similar device which was not as convenient as the final development. This rule is particularly true in the case of transitional devices of the Middle Ages. Because the surviving instruments are rare, scholars must speculate that there were some similar devices which existed previously or filled some period of time. For example, there is a fourteen‐century Egyptian quadrant made of ivory. This instrument bears some interesting astronomical information and was made by Ibn al Sarraj (1328‐1329). Al Sarraj was a brilliant astronomer, but his writings indicate that he also made astrolabes.

154 Arunachalam, B. 2009, p.202. 155 Arunachalam, B. 2009, p.202. ‐ 127 ‐

Figure 54: Fourteen‐century Egyptian Quadrant. This instrument is made in ivory and serves two latitudes (Howard R. Turner, 2002. p.99).

On the other hand, figure 54 shows a device on display in the Museum of History of Science at Oxford. Obviously, this device is a rectangular board carved with a quadrant. According to the explanation by the museum, this tool was made in 1558 by a friar named Miniato Pitti.156 This board is carved with the zodiac signs, which represent how observers relied on the solar path to identify the date. Moreover, because the device was invented in Venice, it also represents the commercial trade controlled at that time by Italians in the Mediterranean. The merchants of Venice and their Muslim counterparts controlled the commercial trade from Europe to East Asia. This fact meant that these people carried the material maritime technology, and these instruments exist as evidence of the connectio. No matter how Pitti’s board and the quadrant are interpreted, no matter which one came first, such a device could not be invented without an undestanding of astronomical theory and appear suddenly. The development of these devices relied on the theories of Ptolemy and on the observation of experiences for several generations as they transited among different cultures.

156 Miniato Pitti was a scientis of the famous Pitti family in Venice. He had a good frien named Giorgio Vasari. Miniato Pitti and Giorgio Vasari had been to the design exhibition of la Sala delle Carte Geografiche. After that, Miniato Pitti’s student named Egnazio Danti completed fifty‐three diagrams of geography by Ptolemy. ‐ 128 ‐

Figure 55: A Quadrant‐like Board. This photo was taken in Museum of the History of Science, Oxford, Auguest, 2013.

Moreover, this device, which could be called quadrant, was designed with the observer’s location in mind. A string indicated the stars against a movable grid on the back of quadrant. The makers of the devices mentioned above and in the diagrams clearly absorbed Ptolemy’s stereographic knowledge and presented it to the Islamic world. These men used these similar devices well. For instances, one such device can be found in the diagram of the sixteenth century Nusratnamab, which shows an astronomer observing a meteor with a quadrant.157

157 Turner, Howard R. 2002, p101. ‐ 129 ‐

Figure 56: Astronomer Measuring Comet with Quadrant. This illustration comes from the Nusratnamab, sixteenth Century (Howard R. Turner, 2002, p101).

With the passage of time, the quadrant became well‐used and popular in maritime arts until the sixteenth century. At that time, quadrants were even made of brass and could include scales with the trigonometric functions. They also carried a stereographic project of the ecliptic and reproduced any condition necessary for navigation.158 Thus, quadrant worked well until the development of the sextant for navigation in seventeenth century.

158 Turner, Howard R. 2002, p100. ‐ 130 ‐

Figure 57: Sixteenth Century Brass Quadrant from North Africa (Howard R. Turner, 2002, p100).

Conclusion Zheng He led his fleet from Nanjing to Sumatra and crossed the Indian and Arabian Oceans, then arrived at Hormuz. Actually, this maritime passage had already been developed for several generations. It can be traced to the second century, when there was already a record of this route. Moreover, the Buddhist monk, Faxian also took this sea route from India to Sumatra and back to Guanzhou in the fifth century. Before the Tang Dynasty, the city Quanzhou had developed but it became a big harbor in the Song Dynasty. At that time, not only Quanzhou but also Guanzhou attracted lots foreign merchants to do business. Chinese merchants sold silk, tea and porcelain and bought fragrances, medicine, and other goods from other countries. Through these commercial improvements of finances in the Song Dynasty, the Song Dynasty government encouraged people to have business interactions with foreigners. The result of these financial interactions extended to cultural interactions, in fields such as religion.

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According to Zheng He, his voyage can be separated into two sections. The route from southeast China until Sumatra area used the “compass‐needle route” (針路) for navigation. In these areas, sailors normally followed the coastline or islands and relied on generations of experience to arrive at their goals. However, the route from Sumatra to Ceylon and from Calicut to Hormuz were in the open‐ocean. Without any landscape or islands to identify their location, understanding the direction and time became important, especially for measuring how long they had been sailing. Thus, sailors measured the angle of stars and horizon and worked with the zām method. Moreover, sailors relied on the monsoon which blew toward the northeast in winter and toward the southwest in summer. And this navigation of open water is a very different method of navigation than the “compass‐needle route” which worked near the coastline. In this case, sailors used the abdāl method to apply the bright stars of the lunar mansions in accounting for the passage of time. Thus, they could sail successfully even without precise clocks to measure time. In addition, they used the qiyas method to understand the latitude of ship by measuring the angle of the Pole Star. At the same time, devices such as the qianxin ban, the kamal, and even the astrolabe developed to measure this angle. Because all the heaven bodies rotate around the North Pole, sailors used the fettering method to memorize the position of each bright star and the constellations. These stars were not only used to measure the time, but also to tell the navigators the directions. The heavenly bodies also acted as a calendar. To use the stars in this way, sailors considered the bright stars which appeared toward the west in the evening and in the early morning before sunrise. The stars which were near the horizon not only tell the time but also tell the direction. In this way, the local sailors used a “star compass,” unlike Chinese sailors who used the magnetic needle compass. The heavenly bodies such as Sun, Moon, and stars are important and necessary elements of navigation. At the end of the Treatise on Armament Technology, there are four diagrams called the Guoyang qianxin tu 過洋牽星圖. They described the sea‐routes to cross the open‐sea and the return voyages: one pair of diagrams is from Sumatra to Ceylon, another is from Calicut to Hormuz. Thus, combined with the record of Zheng He’s voyage from Qianwen Ji, the

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constellations used by Zheng He can be understood. For example, figure 53 containst the Pole Star, the Cassiopeia, the Southern Cross and Vega. On the other hand, several cultures existed along this sea‐route. The phenomenon of linguistic borrowing applied not only to the astronomical knowledge but also to the name of units of measure and instruments. For instance, the zhi in Chinese and isba in Arabic both mean “finger”. The instrument which is called ra‐p‐palagai in the Malayalam and kau‐velli palagai in Tamil is the same device which is called qianxin ban in Chinese. In addition, the development of a theory and the invention of an instrument which relies on a long history of experience in applying the theory. Both the development of the theory and the creation of the instrument overlap in their period of development. The astrolabe is one of the examples. This instrument was used for observation of the position of stars and can be traced back to the time of Ptolemy. Observers normally used the quadrant part to identify time by the stars. Thus, the astrolabe developed into the similar device of a quadrant inscribe on a board which was made at Venice in sixteenth century. Moreover, lots of other quadrants were made from around thirteenth to about the sixteenth century. These devices played an important role in navigation and they may be found in museums nowadays. All of these instruments carried a stereographic projection which was derived from Ptolemy but which Arabic scientists had absorbed well. The transmission and interaction of knowledge can be explained by geography in this case. The quadrant‐like board of the Venice instrument presented an idea similar to the astrolabe and quadrant, which Arabs already used quite well. Thus, both theories and devices not only develop with time, but also travel along the lines of cultural communication. In conclusion, there are several civilizations on this sea‐route. The development of the sea‐ route had occurred for a long time before Zheng He’s voyage. The development of maritime technology influenced cultural communication and inspired more cultural interaction. It not only developed business connections but also improved the transmission of knowledge. Once established, this sea‐route and the cultural communication became a positive feedback loop. The similarities of the linguistic borrowing phenomenon and instrument development are the evidence for the transmission of ideas. Zheng He connected several bright spots of achievement, particularly the religious relationship, the development maritime technology, and financial ‐ 133 ‐

success of traders. Like the stars in the fettering method connected to one another to produce a constellation, these points worked together to direct Zheng He’s voyage, which increased cultural interaction and commercial development.

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Conclusion

The great voyage of Zheng He who commanded the fleet successfully navigated from Nanjing to Southeast Africa and Hormuz. At first, this voyage followed the coastline of southeast China and Vietnam but after Zheng He departed from Sumatra and Longxian Island, they had to sail through the open‐seas in the Indian Ocean to arrive at Ceylon and India. Then, after departing from Calicut, they sailed the open‐seas again and arrived at southeast Africa and Hormuz. To complete this voyage, sailors paid careful attention to the direction and time. For this reason, ancient people observed the regular movements of the Sun, Moon and stars so that they might understand the passage of time. After gathering experiences from several generations, ancient astronomers made calendars by the movement of heavenly bodies, especially the sun and moon. Thus, there the lunar mansions developed in the long course of observations. Coincidentally, lunar mansions existed in different civilizations such as China, India, and Arabia. Even though the lunar mansions developed in different places and grew up with their cultures, the number of mansions all eventually became twenty‐eight and the names of some asterisms were the same between these cultures. For example, the weixiu 胃宿 in Chinese and the al‐Buṭain in Arabic both mean “stomach.”159 This similarity suggests that people could develop similar ideas or people got similar ideas by inter‐cultural communication at that time. Moreover, the lunar mansions helped people understand the lunar path. In this way, observers used the lunar path not only to help predict lunar positions but also relied on the phase of the moon to understand the date. In addition, the asterisms near which the moon stood on the lunar path also told observers about the time and direction. To count the time passing, the zām was an important method which worked well for sailors in the Indian Ocean. This measurement of time was used in ancient India.160 This method was reckoned according to the angle of stars from the horizon and separated the day into eight

159 Tibbetts, G. R. 1981, p.81. 160Arunachalam, B. 2009, p.202. ‐ 135 ‐

parts. A zām corresponded to three modern hours. It was a useful method for navigation and sailors could rely on stars’ movement to understand time passing and how long they had been sailing. Thus, this navigation method was very different from the traditional Chinese navigation method which relied on the magnetic‐needle compass and worked with the zhenlu bu. Since the zām was marked by the stars rising in the east and setting in the west, it is also meant that sailors could rely on stars’ altitude to identify time. Alternately, when a boat was sailing from north to south, the angle between horizon and the Pole Star changed one isba in eight zām. For this reason, zām not only means the angle of isba but also refers to the distance travelled in however much time had passed. This is one of the famous navigation methods, called qiyas. Qiyas can be assumed to be a general set of navigation methods. The most famous and important of the qiyas is the technique of using the Pole Star. The qiyas method work with the angular unit named isba, but it also worked with the Chinese term zhi, which also meant finger. Zām could also represent the arc of heaven. It corresponded with the angular measurement of the stars rising and setting for time measurement at the same time. Moreover, other navigation method such as abdāl and fettering were also the parts of the methods necessary for sailing the open‐seas. Abdāl was found according to two bright stars on the same altitude from the horizon, with the result that the navigator could recognize the meridian. After finding the meridian and predicting which constellations will pass this line, the in (تكبيل) navigator could use this portion of the sky to do time measurement. Moreover, al‐qaid Arabic has the same meaning as qian in Chinese: both mean “fettering.” Fettering is the method by which observers could memorize all the stars in the sky. For example, from Ursa Major, navigators could easily find the Pole Star. In this case, sailors could easily identify the relative position on a cloudy day. The Indian Ocean sailors were also familiar with the monsoon rule: there is a north‐east wind in winter and a south‐west wind in summer. Thus, they understood these winds and decided their departure and return days. In addition, the coastline views, plants and animals (such as different fish and seagulls) were also signs by which sailors gained an idea of their location. By examining all these conditions, the maritime technology had developed well enough to sail across the open‐sea successfully. ‐ 136 ‐

The theories and instruments also complemented each other. To identify direction, there were two types of method which existed on this sea‐route. One was according to magnetic needle compass; the other relied on stars. Navigators used the needle compass to identify direction. They followed the guide book which had been compiled over several generations. This book was call Genlu Bu, or Zhenlu Bu. The second method relied on the stars to identify directions and can be called a “star compass”. Sailors familiar with stars’ relative positions observed them at dusk to determine the directions. This method also worked with zām, the special time‐measurement system of the Indian Ocean. Moreover, the “star compass” could also represent the specific harbors sometimes. For example, sailors used the “star compass” to refer to other harbors when they arrived Socotra Island. Through the “star compass,” sailors had a reliable method to identify directions and time. They had another device which also relied on stars and worked in maritime navigation. It was called the astrolabe. It can be traced from Hellenistic era and was developed from the ideas of Ptolemy. Thus, this instrument measured the stars’ altitude from the horizon. From this measurement, sailors knew the date and time by stars position. There were several methods to project the stars onto the astrolabe and the user could identify the latitude and time according to these methods. This brilliant device worked like a computer to resolve questions about time and direction questions by reference to the stars. A similar device was used to measure the angle between the stars and horizon. This device was called qianxin ban in Chinese and kamal in Arabic. There were some different types of this instrument. One had a single board and a line which had knots. Sailors used the knots on the line to let board fit the distance between the Pole Star and the horizon. The second type was a set of different boards but there were no knots on the line. This type of measurement device required the sailor to make the line tight and then choose the best fit among the boards of different size to measure the star’s altitude. It was the type typically described in Chinese sources. In addition, some studies mention the lingtian chi as the original type of qianxin ban in Chinese. However, most of these were instruments like a sundial which measured a shadow to understand time. It would have been hard to carry this instrument on a boat and it was not useful to measure the star’s altitude. It was a traditional device of China and used for ‐ 137 ‐

measurement.161 A third type had both different sized boards and knots on the line which connected the boards. This type of instrument was normally used in Kavaratti Island which lay to the southwest of India. To measure the angle between the stars and horizon, different people chose different types instruments. This choice represented the several cultures on this sea‐route. This unique instrument developed was from several cultures on this sea‐route by sailors rather than from some specific culture. Before Zheng He’s voyage, this sea‐route had been developed for several generations. For example, the monk Fa Xian took this route from India to Sumatra then back to Guanzhou. After several generations, many foreign merchants came to Guanzhou and Quanzhou to do business. These merchants bought silk, tea and porcelain from China and sold fragrances, medicine, and others wares to China. Until the Song Dynasty, the government encouraged more business from abroad to solve financial problems. When the commercial interaction developed, it also helped the cultures communicate about topics such as religion and even the knowledge behind the technology of different cultures. For example, the Pu family in Quanzhou played a role in Zheng He ‘s voyage. Zheng He’s fleet relied on the “compass‐needle route” to sail from Nanjing. They simply followed the coastline of southeast China and Vietnam until Sumatra. But from Sumatra to Ceylon and from Calicut to Hormuz, they had to cross the open‐sea. Without any landscape or islands to identify their location, the stars became the most important condition. Sailors measured the angle between the stars and the horizon and they combined these measurements with the zām method to recognize time and direction. Moreover, they skillfully used the monsoon winds as their power and arrived successfully. When they crossed to the open‐sea area, they relied on the qiyas method and used the qianxin ban to measure the Pole Star to keep on the correct path. After they used the device and got a reading in units of isba, sailors not only recognized their position but could also convert this unit into the zām method to understand the time. These units could also work with the abdāl method and lunar mansions to count the passing of time. Moreover, because sailors used the “fettering” method to memorize the star positions, it was useful to identify them in cloudy day. There are four

161 Huang, Shengzhang 黃盛璋 2010, p.124. ‐ 138 ‐

diagrams called the the Chart of Sea‐Crossing by Fettering Stars at the end of the Treatise on Armament Technology. These diagrams recorded the sea‐routes to cross the open‐sea and the return voyages: one pair of diagrams is from Sumatra to Ceylon, another is from Calicut to Hormuz. Combined with Zheng He’s dates for his voyage from Qianwen Ji, Zheng He clearly used some specific stars or constellations as guides. For example, Ursa Minor, Cassiopeia, Pleiades, the Southern Cross, Canopus and Vega appear among the navigational constellations. In addition, we can find evidence of linguistic borrowing phenomena. This evidence exists in astronomical knowledge and the terminology of instruments. For example, the chi in Chinese and isba in Arabic share the same meaning of “finger”. This similarity reinforces that there were several civilizations on this sea‐route and they communicated with each other in the course people sailing. Since they communicated to each other, the theories and devices could not appear without taking form over several generations. Furthermore, the transmission and cultural interactions can be explained by geography. For instance, the astrolabe carried the stereographic projection from Ptolemy in Greece to the Arabic astronomers who absorbed it and extended it well. Due to the fact that the astrolabe was a method to measure the star’s altitude, the quadrant which was developed later for maritime uses, stands as a derivation of the technology. The quadrant was one kind of development of an original device. In addition, the quadrant‐like board of the Venetian instrument presented an idea similar to the astrolabe and quadrant, and represented the Arabic and Ventian merchants had some interactions. In short, both of these situations show that theories and instruments not only developed with time but also travel geographically with cultural communication. Thus, Zheng He had perfect timing. He undertook his voyage soon after the development of maritime technology permitted it, at a time when the religion relationship flourished between China and the Middle East, and during a period of financial success from commercial trade. This great voyage not only departed under these conditions, but also improved these conditions through its success. Exploration and trade form a positive feedback loop, resulting the cultural communication in topics like religion and navigational science getting strong.

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In this regard, the Treatise on Armament Technology presents evidence of cultural communication. I agree with Huang Shengzhang’s opinion that this sea chart presented different elements of maritime technology from different cultures. 162 For example, the magnetic‐needle routes marked with gen were typical of traditional Chinese maritime technology, while the information about the stars and the zhi were familiar to most sailors in the Indian and Arabic Oceans. Thus, these elements of information were also recorded on this sea chart. In this way, the sea charts of the Treatise on Armament Technology prove the cultural interactions. In conclusion, there were many details that could be developed from this sea‐route. First, how did people track time‐passing in these different cultures? Secondly, the rules for finding the specific harbors from Socotra Island, combined with the wind compass and star compass, could have some possible connection with the wind roses marked on sea‐charts. In addition, how the instruments were devised and which theories were employed could also form the basis of interesting studies in the future.

162 Huang, Shengzhang 黃盛璋 2010, p.122. ‐ 140 ‐

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