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History of Cartography By Trista L. Pollard

Our view of the world has changed since 1500 years ago. The maps and globes we use today are very accurate. They show more details. You can see cities and countries. They show landforms and landmarks. Our maps now have a standard coordinate or grid system. This measurement system helps us to locate places on Earth. But what about the first maps? What are they like? How were they made? Let's take a journey into the history of cartography.

Cartography is the science of making maps. Today's cartographers use computers and cameras to help make maps. This is called remote sensing. Cameras are placed or mounted on airplanes. These cameras take pictures of the Earth's surface. Satellites in space are also used for cartography. Mapmakers in the past had much less technology. They used observation and stories from sailors to make maps.

Most early scientists believed the Earth was flat. Imagine sailing from your country and falling over a cliff! That's what people thought. They also thought Earth was a flat disc. The center of the disc was filled with people. The outer edges of the Earth were empty. A world map made as early as 500 B.C. showed a disc with two continents. These continents were Europe and Asia. Both were surrounded by an ocean. That makes sense! Most people only knew about their surrounding or immediate area. Geographers also found early maps of the Pacific Ocean. They were made by navigators from Polynesia or the Pacific Islands. These maps date back to 1500 B.C. The navigators used shells and the ribs of palm tree leaves. With these items, they mapped the currents and waves of the Pacific. Shells were used to mark islands they saw on their journey. The maps were 18 to 24-inch squares. Polynesian sailors used these maps as they sailed in the South Pacific.

Many of the early maps focused on towns and cities. Geographers have found early maps made of clay. The maps were scratched into clay tablets. These maps showed canals, walls, houses, and gates. Many towns were surrounded by walls for protection. Geographers estimated the maps were over 4,000 years old. They were from Mesopotamia in the Middle East. Ancient Egyptians also made maps. In 250 B.C., a scientist named Eratosthenes calculated the Earth's circumference. Circumference is the distance you travel around the Earth in a complete circle. His estimate was very close for the time. It was 37,700 kilometers. The Earth's circumference around the equator is 40,075 kilometers (24,902 miles). If you travel through the poles, the circumference is 40,007 kilometers (24,860 miles).

Another Egyptian cartographer was Ptolemy. In about 100 A.D. he made the first map with lines of latitude and longitude. He even published our first atlas called Geographia. The book had 8 volumes. In his atlas, he gave coordinates for over 8,000 places. It also had a world map and maps of other regions. Ptolemy's world map also used a different circumference. He calculated the circumference to be 29,000 kilometers. Years later, Christopher Columbus is believed to have used Ptolemy's map. That means Columbus used a map with an incorrect circumference. You have to wonder if this affected his trip.

It was not until the 1400's that people became interested in maps. This was the Age of Exploration. Explorers and sailors were leaving Europe to find all-water routes to Asia. These sailors brought back valuable information. This information was about our continents and oceans. They also discovered one very important fact-that the Earth was round. Scientists used Ptolemy's atlas to help with mapmaking. Printing presses were also invented during this time. Now maps that were drawn by hand could be copied. With more ships leaving Europe each day, more maps were needed. Prince Henry of Portugal was a very important man. He studied the information from sailors and other mapmakers. He used this information to help make better navigation tools. He also helped to build better ships and design more accurate maps. Due to his work, more explorers traveled overseas. Name Date

Gerhardus Mercator is one of our most famous geographers. In 1569, he published a world map. It wasn't just any world map! It had 18 sheets! He also drew his map to show the shape of the Earth. This is not easy to do. When cartographers try to draw our sphere on flat paper, some of the sphere becomes distorted. The shape and size of the sphere becomes changed. Mercator drew that Earth as a flat map. However, he figured out a way to show its shape and correct position of the continents. Today we call his drawing the Mercator Projection. A projection is a flat picture of a sphere. There was one flaw with Mercator's map. His map makes Europe, Asia, and North America very large. Africa and South America look a lot smaller. Even with this flaw, Mercator's map was used for hundreds of years. Today we use other map projections.

By the end of the 1800's, cartographers used more science to make maps. They used instruments to help plot locations. These instruments were telescopes, sextants, and chronometers. Now instead of maps for exploration, they are used for other purposes. Maps were used for the military. As countries became involved in wars, maps were used for planning. Many organizations began that focused on geography. In 1821 the Societé de Géographe de Paris was started in France. It was started to help map French territories and areas of trade. The Royal Geographical Society began in Great Britain in 1830. This organization encouraged exploration of Africa and Australia. In the United States, the National Geographic Society was born in 1888. Its headquarters is located in Washington, D.C. The society promoted understanding of the Earth's geography. This is still their goal today.

Most of our planet's surface is mapped. In fact, there are areas of the Earth that are shown with a lot of detail on maps. Explorers have mapped the ocean floors. However, they are not as detailed as the land surfaces. Our maps today include human-made features and natural features. We have paper road maps and computer maps. You can even have a small computer in your car to tell you directions. Maps have come a long way since the "world is a disc" days. They are more detailed and more accurate.

History of Cartography Questions

1. Based on context clues, what does the word flaw mean?

2. Some of the earliest known maps on Earth were made about ______. A. 10,000 years ago B. 4,000 years ago C. 2,000 years ago D. 2,500 years ago 3. Most early scientists believed that the Earth was a flat disc. A. False B. True 4. What is the main idea of paragraph eight? Name Date

5. Ptolemy's atlas contained coordinates for over 8,000 places. How did he get these coordinates?

6. Order these geographers for earliest discoveries to latest discoveries.

A. Prince Henry of Portugal B. Eratosthenes C. Ptolemy D. Gerdhaus Mercator 7. Maps were used for military purposes since the early 1500's. A. True B. False 8. National Geographic Society began in the United States in ______. A. 1886 B. 1830 C. 1821 D. 1888

Why did early scientists believe that the Earth was flat and a large disc? What observations may they have used to make this assumption? Name Date

You are one of Prince Henry's sailors. You have just been sent on a journey to explore the west coast of Africa. Write a journal entry that describes your observations. Make sure you describe the land and water features that you have seen on your journey.