DOCSLIB.ORG

Treatise on the Principal Mathematical Instruments

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Treatise on the Principal Mathematical Instruments : 1§| ;^hr: ■ 7>/7 ;•- : --■*» m - - --•'. .1' ,' * i, !rf * agis- Mi?: v ••• V.v- -% '. ... *%■-, f m f' ■ .. v ■ " , '.v ; 1 ■'. • •. • ' ■: A 2 .1 ; . '•?' . \ . •\1. - ■ ■ • . ■ V ' . :\ *jS V •• 1 jV-;?' . ' ;f ~ .v ' /- 7 .•,: * •' • Ufa; C-'-^i^yy r'~• 7 ■“7*'C7?>' .fit • V-•; . I \x- S->- • • • •..■ - • •-. - • • >'.^n ..._V •. - • ; '.7*-‘: -' .r.f--’, ' ' '• r*sWik' * v=.. v \-r- Sp'&'cAi '.'7 . ■-■ ■ 15,?: v -77 -.*■ 7>; ” v # .' • v’V&V*,‘ • •• A TREATISE . •! ■^77' .. V j • I* •.' • -: . ?• r 7 - 7 > ON THE ■ ' r. V . ''S'-vL" *.-»■■!! ! , ' PRINCIPAL MATHEMATICAL INSTRUMENTS i • i• • .. ' USED IN SURVEYING, LEVELLING, AND ASTRONOMY, fyc. Sf€. Price Five Wk 77'J ; t!. ... ^ V/': : -. A .««:r if • •••■<• pig|«|i^Kv-:; ^ « ;7;,*1 : ' i- ■7 •' • •; • '••' •' ' A TREATISE ON THE PRINCIPAL M AT II EM ATI C A L INSTRUME NTS, EMPLOYED IN SURVEYING, LEVELLING AND ASTRONOMY, Sfc. Sfc. Digitized by the Internet Archive in 2018 with funding from Wellcome Library f https://archive.org/details/b29298854 A TREATISE ON THE PRINCIPAL MATHEMATICAL INSTRUMENTS EMPLOYED IN SURVEYING, LEVELLING, AND ASTRONOMY: EXPLAINING THEIR CONSTRUCTION, ADJUSTMENTS, AND USE. WITH AN aittr Cafclrsc -- BY FREDERICK W. SIMMS, ASSISTANT AT THE ROYAL OBSERVATORY, GREENWICH, AND FORMERLY EMPLOYED ON THE ORDNANCE SURVEY. LONDON: PRINTED BY T. BENSLEY, CRANE COURT, AND SOLD, FOR THE AUTHOR, BY MESSRS. TROUGHTON AND SIMMS, 136, FLEET STREET. 1834. iEntcretr at stationers’ P?atL PR E F A C E. rn I he want of a work containing a concise and popular description of the principal Instruments used in Practical Astronomy and Surveying has long been felt, as the requi¬ site information with respect to such instruments can only be obtained by consulting various expensive publications, which are not within the reach of many to whom such information is highly interesting and important. It was the original object of the writer of this little tract, to place at the disposal of the young surveyor a description of the instruments which are required in his profession, and such an account of the method of examining and rectify¬ ing their adjustments, as would enable him to obtain from them the most accurate results ; but he found that, without greatly increasing the size of the book, he might materially add to its utility, by including in his plan the most approved Astronomical Instruments, that amateur astrono¬ mers as well as scientific travellers might have at hand a manual of instructions, which would enable them to use their instruments with the utmost advantage. Usefulness being the author’s chief object, he has not scrupled to extract from the works of others whatever he found adapted to his own purpose; and to some kind lite¬ rary and scientific friends he is under obligations, for which, if he had obtained their permission, he would be glad to thank them by name in this place. Of Surveying Instruments, those only have been de¬ scribed which are applied in modern practice, no reference VI being made to those which, having been superseded by better ones, may be said to be out of use. To the article on Levelling has been added a description of Mr. Troughtqn’s Improved Mountain Barometer, with an easy and accurate method of computing differences of level from barometrical observations. Table II. employed for this purpose, has been carefully recomputed from Mr. Baily’s Formulae. The other tables will, for their several purposes, be found convenient and useful. Tables I. and vin. are new. Much attention has been paid to the accuracy of the formulae given for performing the various computations, and each has been thrown info the form of a practical rule, that persons unacquainted with algebraic notation may be enabled notwithstanding to make the requisite calculations. With respect to such astronomical problems as appertain chiefly to Navigation, and require extensive and special tables for their convenient solution, it has been thought better to omit all reference to them in this work, as in Mr. Riddle’s Treatise on Navigation, Captain Thompson’s Lunar and Horary Tables, and other similar works, all ne¬ cessary information on the subject may be readily obtained. The Appendix relates chiefly to the protraction of the work after a survey has been completed, and seems a suit¬ able supplement to the account of Surveying Instruments given in the preceding part of this treatise. C 0 N T E N T S. SURVEYING INSTRUMENTS. The Land Chain.Page 1 The Surveying Cross and Optical Square. 2 The Prismatic Compass... 3 The Vernier. 4 The Theodolite... 7 Adjustments of the Theodolite. 10 Method of observing with the Theodolite. 14 The Plane Table. lb Method of using the Plane Table. 19 LEVELLING INSTRUMENTS. The Y Spirit Level. 21 Adjustments of the Y Level. 22 Troughton’s Improved Level. 23 Adjustments of Troughton’s Improved Level. 25 The Method of determining Distances by a Micrometer Scale 26 Levelling Staves.!. 26 Troughton’s Levelling Staves. 27 On Levelling. 28 „ With the Spirit Level. 29 ,, With the Theodolite. 30 Description of the Mountain Barometer... 31 Levelling with the Mountain Barometer... 32 ASTRONOMICAL INSTRUMENTS. The Sextant . 55 The Principle of its Construction. 34 Description of the most approved Sextant. 55 Adjustments of the Sextant. 36 Method of Observing with the Sextant. 39 Troughton’s Reflecting Circle. 41 Directions for observing with the Reflecting Circle.. 44 The Box Sextant.:. 44 Adjustments of the Box Sextant. 46 The Artificial Horizon. 46 Roof Horizon... 47 Plane Glass Horizon. 47 The Dip Sector. 48 Method of observing with the Dip Sector ... 50 VI11 The Portable Transit Instrument.Page 51 The Adjustments of the Transit Instrument. 55 Methods of determining the Meridional Deviation of Transit. 55 by a Circumpolar Star. 55 by two Circumpolar Stars. 56 by High and Low Star... 58 Method of observing and registering Observations. 59 Finding the Error of a Time-Keeper. 62 Correcting observed Transits for the Error of Collimation. 64 ,, ,, for Error of Level. 65 ,, ,, for Meridional Deviation. 66 Method of Determining the Longitude by Observed Transits of the Moon and Moon Culminating Stars. 67 Professor Bessel’s Method of finding the Latitude with a Transit Instrument... 70 The Altitude and Azimuth Instrument. 71 The Adjustments of the Altitude and Azimuth Instrument. 74 Description and Adjustments of the Reading Microscope. 76 Use of the Altitude and Azimuth Instrument. 78 To compute the Reduction to the Meridian. 79 To determine the Latitude of a Place. 80 Method of Observing equal Altitudes and Azimuths. 81 Determination of Time by equal Altitudes. 82 ,, the True Meridian by equal Azimuths. 85 ,, ,, by a Circumpolar Star. 85 ,, ,, by the Azimuth of a Celestial Object. 86 Method of finding Differences of Latitude and Longitude by Trigonometrical Measurement. 87 Method of finding the Longitude by the Eclipses of Jupiter’s Satellites. 88 APPENDIX. On the Protraction of Angles. 89 Method of performing and plotting a Road Survey... 91 Description of the best Circular Protractor. 95 Plotting Scale. 97 Station Pointer, &c. 98 TABLES. 1. To Reduce the Apparent to the True Level. II. For determining Altitudes with the Barometer. III. For Converting Intervals of Sidereal into corresponding Intervals of Mean Solar Time. IV. For Converting Intervals of Mean Solar into corresnonding Intervals of Sidereal Time. V. & VI. For Computing the Longitude from the Observed Transits of the Moon and Moon Culminating Stars. VII. For Computing the Reduction to the Meridian. VIII. The Length of a Second of Longitude and Latitude in Feet, for different Latitudes. A DESCRIPTION OF THE PRINCIPAL INSTRUMENTS EMPLOYED IN SURVEYING, LEVELLING, # ASTRONOMY, WITH THEIR ADJUSTMENTS AND USE. SURVEYING INSTRUMENTS. THE LAND CHAIN. Gunter’s Chain is the one now commonly used in taking the dimensions of land; it is sixty-six feet, or four poles, in length, and is divided into 100 links, each of which is joined to the next by three rings ; the length of each link, including the connecting rings, is 7,92 inches, and at the end of every tenth link is attached a piece of brass (each of a different shape,) for more readily count¬ ing the odd links. “ The English acre contains 4840 square yards, and Gunter’s chain is 22 yards in length, and the square chain, or 22 multiplied by 22, gives 484, exactly the tenth part of an acre; and ten square chains are equal to one acre; consequently, as the chain is divided into 100 links, every superficial chain contains 100 multiplied by 100, that is 10,000 square links ; and 10 superficial chains, or one acre, contains 100,000 square links. " If therefore the content of a field, cast up in square links, be divided by 100,000, or, (which is the same thing) if from the con¬ tent we cut off the last five figures, the remaining figures towards the left hand give the content in acres, and consequently the num¬ ber of acres at first sight; the remaining decimal fraction, multi¬ plied by 4, gives the roods, and the decimal part of this last product, multiplied by 40, gives the poles or perches.” Short distances, or off-sets from the chain line, are usually mea¬ sured with a rod, called an off-set staff, the most convenient length for which is 6 feet 7,2 inches, being equal to 10 links of the chain, and it should be divided accordingly. With the chain must be provided ten arrows, which may be made of strong iron wire, about 12 or 15 inches long, pointed at one end for piercing the ground, and turned up at the other, in the form of a ring, to serve as a handle: their use is to fix in the ground at each extremity of the chain whilst measuring, and to point out the number of chains measured.
Load more

Recommended publications
  • 'The Early Development of the Davis Quadrant', In: Bulletin of The
    The Early Development of the Davis Quadrant Nicolàs de Hilster Introduction Observation Methods By the end of the 17th century one of the According to Atkinson the ‘... Instrument is most popular instruments for taking alti- rarely used otherwise than to observe the tudes of the sun was the Davis quadrant Sun’s Meridian Altitude...’.4 The alternate (Fig. 1), of which it is generally accepted use Atkinson referred to was perhaps the that it was fully developed by 1604.1 Over determination of longitude by lunar dis- the years during my research of early navi- tance as described in a work printed for J. gational instruments I found clues showing Wilford in 1726.5 For measuring the sun’s that 1604 was the start of its development meridian altitude the shadow vane was set rather than the end. The development went at a whole number of degrees, some 15-20 through several stages, relating to the frame, degrees lower than the expected zenith dis- the scales and the vanes. In addition to that tance of the meridian passage of the sun. also the name of the instrument changed While standing with his back towards the over time, not becoming ‘Davis quadrant’ sun – instruments used in this way were until the last quarter of the 17th century. henceforth given the general name ‘back- This article deals with the early develop- staff’ – the observer would align the slit in ment of the instrument and tries to provide the horizon vane with the horizon, while evidence that the instrument was not fully trying to coincide it with the upper edge of developed until the 1670s.
    [Show full text]
  • The Spiegelboog (Mirror-Staff): a Reconstruction
    The Spiegelboog (mirror-staff): a reconstruction N. de Hilster Introduction might lead to confusion in this article. I will The upper vane on the cross is called ‘shad- At the end of the 16th century one of the therefore refer to the instrument John Da- ow-vane’, the lower one ‘sight-vane’. They th principal instruments for celestial naviga- vis invented as back-staff and to the 17 had fixed positions, enforced by brass pins, tion at sea was the cross-staff (Fig. 1 A. The century development as Davis Quadrant. by which they can be pre-set at three differ- ent distances symmetrically from the staff others were the mariner’s astrolabe and The main difference between the hoek- the quadrant, but thanks to its accuracy along the cross. The sliding horizon-vane boog and the Davis Quadrant was that the could then be used with or without the (and price compared to the astrolabe) the scales on a hoekboog were engraved on cross-staff would eventually replace both mirror for backward observations. Without chords while on a Davis Quadrant they the mirror the shadow of the shadow-vane instruments. The cross-staff is a wooden were engraved on circle segments. Usu- instrument consisting of a square staff and was cast onto the horizon-vane, which had ally the smaller chord of the hoekboog was a rectangular hole through which the hori- up to four sliding transoms or vanes. For engraved in 10 degrees intervals while the each vane a scale was engraved on one of zon was seen.
    [Show full text]
  • Hadley's Octant (A. D. 1731)
    HADLEY’S OCTANT (A. D. 1731). On the occasion of the second centenary of the invention of reflecting instruments and in accordance with the usual custom of reproducing in the Hydrographic Review documents of particular interest connected with the history of nautical and hydrographic science, the communication made by John Hadley to the Royal Society of London on 13th May, 1731, is repro­ duced hereafter in facsimile. This communication was published in N° 420 of the Philosophical Transactions. It appears that the oldest document in which allusion is made to the principle of reflection by plane mirrors, as applied to the measurement of angles, is the History of the Royal Society of London by B ir c h . In this book, under the date of 22nd August, 1666, it is stated “ Mr. H o o k mentionned a new astronomical instrument for making observations of distances by reflection”. In another place it may be read that on the 29th August of the same year, H o o k spoke of this instrument again, it being then under construction, to the members of the Society. They invited him to submit it as soon as possible and this was done on 12th September of that year. The instrument submitted by H o o k differed in important details from the modern sextant; it was provided with but one mirror and thus was a single reflecting instrument. This was the fundamental defect which made it impos­ sible for H o o k ’s invention to be a success. However, the idea of using reflection from a plane mirror for the measu­ rement of angles was not forgotten and, in spite of H o o k ’s want of success the principle was taken up by others who sought to correct the disadvantages of the instrument as first invented.
    [Show full text]
  • “Navigational and Nautical Equipment”
    “NAVIGATIONAL AND NAUTICAL EQUIPMENT” ΑΚΑΓΗΜΙΑΔΜΠΟΡΙΚΟΤΝΑΤΣΙΚΟΤ Α.Δ.Ν. ΜΑΚΔΓΟΝΙΑ΢ ΔΠΙΒΛΔΠΩΝ ΚΑΘΗΓΗΣΡΙΑ: ΠΑΝΑΓΟΠΟΤΛΟΤ ΜΑΡΙΑ ΘΔΜΑ: NAVIGATIONAL AND NAUTICAL EQUIPMENT ΣΗ΢ ΢ΠΟΤΓΑ΢ΣΡΙΑ΢: ΢ΚΔΠΔΣΑΡΗ ΙΩΑΝΝΑ Α.Γ.Μ: 3432 Ημεπομηνία ανάληψηρ ηηρ επγαζίαρ: Ημεπομηνία παπάδοζηρ ηηρ επγαζίαρ: Α/Α Ονομαηεπώνςμο Διδικόηηρ Αξιολόγηζη Τπογπαθή 1 2 3 ΣΔΛΙΚΗ ΑΞΙΟΛΟΓΗ΢Η Ο ΓΙΔΤΘΤΝΣΗ΢ ΢ΥΟΛΗ΢ : Table of Contents INTRODUCTION ......................................................................................................... 5 Chapter 1 - Charts and drafting instruments .................................................................. 5 1.1 Nautical chart ....................................................................................................... 5 1.1.1 Chart correction ............................................................................................. 7 Limitations .............................................................................................................. 7 1.1.2 Map projection, positions, and bearings ........................................................ 8 1.1.3 Electronic and paper charts ............................................................................ 9 Labeling nautical charts .......................................................................................... 9 1.1.4 Details on a nautical chart ........................................................................... 10 Pilotage information ............................................................................................
    [Show full text]
  • No. 694,904. W
    No. 694,904. W. YOULTEN, Patented Mar. 4, 1902. SGHTING DEVICE FOR FIREARMS. (Application filed May 13, 1901.) (No Model.) 4. Sheets-Sheet . Inventor. Vailorne yS. No. 694,904. Patented Mar. 4, 1902. W. YOULTEN. SGHTING DEVICE FOR FIREARMS. (Application filed May 18, 1901.) (No Model.) 4. Sheets-Sheet 2. hitnesses. Zee Inventor: a s vittorneys. No. 694,904. Patented Mar. 4, 1902. W. YOULTEN. SIGHTING DEVICE FOR FIREARMs. (Application filed May 18, 1901. (No Mode.) 4 sheets-Sheet 3. 7fitnesses: Anventor 2...took 87%uchun, 22e.23. 77ttorn e/s. No. 694,904. Patented Mar. 4, 1902. W. YOULTEN. SIGHTING DEVICE FOR FIREARMS. (Application filed day 18, 1901.) (No Model.) 4. Sheets-Sheet 4. WILLIAM YOULTEN, OF WESTMINSTER, ENGLAND. SIGHTING DEVICE FOR FIREARMs. SPECIFICATION forming part of Letters Patent No. 694,904, dated March 4, 1902, . Applination filed May 13, 1901, serial No. 60,114. (No model.) to all whom it may concern: , With reference to Figs. 1 to 5the reflect Beit known that I, WILLIAM. YoULTEN, a ing instrument is shown made in two parts a subject of the King of Great Britain and Ire and b, fitting together by means of cylindrical 5 land, residing at 159 Victoria street, West flanges or projections atc. a. and b are tubes 5 minster, in the county of London, England, square in cross-section. The tube a contains have invented Improvements Relating to the two mirrors die, Fig. 4, and the tube b two Sighting of Rifles and other Firearms, of mirrors fg. Each tube has an aperture, the which the following is a specification.
    [Show full text]
  • Surveying – I Unit I Indroduction and Chain Surveying 1
    SURVEYING – I UNIT I INDRODUCTION AND CHAIN SURVEYING 1. Define Surveying. What are the fundamental principles of surveying? Surveying is an art of determining the relative positions of various points on, above or below the surface of the earth by means of direct or indirect measurement of distance, direction and elevation. The principles of surveying are: (i) Working from whole to part. (ii)To locate a new station by at least two measurements (angular, linear) from fixed reference points. 2. What is the object or purpose of surveying? The primary object of surveying is to prepare a plan or map to show the relative position of the objects on the surface of the earth. It is also used to determine the areas, volumes and other related quantities. 3. Name the different ways of classification of surveys. a. Primary classification (i). Plane surveying (ii). Geodetic surveying. b.Secondary classification (i). Based on instruments used (ii).Based on methods. (iii). Based on object (iv). Based on nature of the field 4. Differentiate between plane and geodetic surveying. Sl.No. Plane surveying Geodetic surveying. 1. The curvature of the earth is The curvature of the earth is taken. neglected. 2. A line joining any two points is A line joining any two points is considered straight. considered as curved line. 3. The triangle formed by any three The triangle formed by any three points is considered as plane points is considered as spherical triangle. triangle. 4. It is done on a area less than 250 It is done on a area greater than 250 Km 2 Km 2 5.
    [Show full text]
  • NV Sail and Power Squadron
    Volume LI Number 6 www.nvsps.org www.BeyondBoating.org www.uspsd5.org July-August 2018 Tour Williams & Heintz Map Corporation September 14, Page 8 Page 4 Next Membership Meeting September 12, 2018 July October 25 Executive Committee Meeting. All members 13 Oktoberfest and General Membership Mtg welcome. at Fairfax Yacht Club August Break for Boating 24 Executive Committee Meeting. All members Take a friend boating! welcome. First meeting at new location TBA. September 12 General Membership Meeting More: http://www.nvsps.org/docs/calendar.pdf 14 Tour Williams & Heintz Map Corp Meetings location Information page 2 26 Executive Committee Meeting Membership Meeting Evenings: Social and Refreshments 1900–1930, Mtg and presentation 1930 Executive Committee Meetings: All are welcome to attend. Starts at 1930 Bridge Officers Scheduled Meetings: Unless otherwise noted, the General Membership Meetings will be held at the BoatUS™ HQ facility at 1930 on the second Wed of each month except for the months COMMANDER Cdr Charles Hurley, JN of Aug. and Dec., and the May and Oct mtgs will be combined 703-455-4828 with other events. Social Time 1900-1930. Any changes will be [email protected] posted in this newsletter or on the Squadron website. EXECUTIVE OFFICER BoatUS Headquarters meeting location: Lt/C Sean Gallagher, JN 880 South Pickett Street, Alexandria VA 22304 703-548-5851 [email protected] From Capital Beltway, take the VA-613/ Van Dorn St exit # 173, towards Franconia. Turn left onto S. Van Dorn St / VA-613 North. EDUCATION OFFICER Turn left onto S. Pickett St. Go less than .5 miles and turn in at Lt/C Dean Markussen,AP 703-751-9178 first the BoatUS™ sign and go to the lighted parking lot in rear.
    [Show full text]
  • Celestial Navigation Net
    Celestial Navigation Net Break out of a frame A Poem in Defense of Lunars Recent Additions here - Land and Sea Collection Message from the webmistress concerning email and other notes - also, please order from Amazon here to keep this site alive! APRIL 2004 Chiamavi 'l cielo e'ntorno vi si gira, mostrandovi le sue bellezze etterne* Welcome to the Celestial Navigation Net! Celestial Navigation is the art and science of finding your way by the sun, moon, stars, and planets, and, in one form or another, is one of the oldest practices in human history. This webpage is an attempt to bring together all of the best Celestial Navigation resources on the internet, with pointers to other resources as well. Find out why we should study Celestial navigation in the age of GPS; get an introduction to Celestial Navigation's history, then take a look at the navigational astronomy page as a background for the theory and practice; teachers, discover how celestial navigation can enliven the classroom, whether your field is earth science, astronomy, math, history, or literature, with special links about Vikings; learn about navigational instruments, including sextants, astrolabes, nocturnals, and planispheres; learn about nonwestern, noninstrument Polynesian starpaths and Wayfinding; read quotations about navigation; check out some schools; or just go directly to the list of resources which lists the sources from the other pages. Other links of interest are here. *The heavens call to you and circle about you, displaying to you their eternal splendors...." Dante, Purgatorio, Canto XIV http://www.celestialnavigation.net/ (1 of 2) [9/6/2004 12:50:10 PM] Celestial Navigation Net Marion-Bermuda Race offers Celestial Certificate All original material copyright 2000 and 2001.
    [Show full text]
  • Space Technology Game Changing Development; NICER/SEXTANT: the Latest Incarnation of Celestial-Based Navigation
    National Aeronautics and Space Administration Space Technology Game Changing Development NICER/SEXTANT: The Latest Incarnation of Celestial-Based Navigation As history has shown, there really is nothing Technology (NICER/SEXTANT). Selected as a new under the Sun. Since the beginning of NASA Explorer Mission of Opportunity in April recorded history, if not before, humans have 2013, the payload will use one of nature’s most facts used the stars to find their way. In 2017, a accurate clocks, pulsars, as navigational bea- team led by two NASA astrophysicists plans cons when it begins operations from its berth to demonstrate a potentially game-changing on the International Space Station in 2017. technology that would use millisecond pulsars These extraordinary objects, which are a sub- to help space travelers and scientific space- group of neutron stars, rotate rapidly, emitting craft navigate the far reaches of the solar powerful beams of light, much like a light- system and beyond. house, from their magnetic poles that sweep The latest incarnation of celestial-based navi- around as the star spins. At Earth, these gation is an experiment called the Neutron- beams are seen as flashes of light, blinking star Interior Composition Explorer/Station on and off at intervals from seconds to, in the Explorer for X-ray Timing and Navigation fastest-spinning cases, milliseconds. NASA ARCHIVED Gold foils of NICER’s 56 X-ray concentrators illuminated during alignment testing. Because of their predictable pulsations, pulsars are highly star of known declination. To do this, the navigator would reliable celestial clocks that can provide high-precision sight on the celestial object with the astrolabe’s movable timing similar to the atomic clock signals supplied through arm, called the alidade, and measure the angle of height the 26-satellite, military-operated Global Positioning Sat- of the object above the horizon, thereby determining the ellite System (GPS)—a space-age navigational capability ship’s position.
    [Show full text]
  • An Analysis of the Development of Celestial Navigation
    AN ANALYSIS OF THE DEVELOPMENT OF CELESTIAL NAVIGATION By WALTER PRIEST MORSE A DISSERTATION PRESENTED TO THE GRADUATE COUNQL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA August. 1953 ACKNOWLEDGMENTS The author acknowledges his indebtedness to his supervisory committee, Dr. Franklin W. Kokomoor, Chairman, Dr. John S. Allen, Dr. Leon N. Henderson, Dr. William R. Hutcherson, Dr. James W. Norman, and Dr. Cecil G. Phipps. All have made con- structive criticisms and valuable suggestions. In particular he wishes to thank Dr. Kokomoor for his encouragement at all times, and Dr. Phipps for his careful editing of this study. TABLE OF CONTENTS Page LIST OF FIGURES , , . , . iv CHAPTER I Introduction o .... 1 II From Early Times to 1400 A.D. ...... 3 III From 1400 to 1600 . .............. 20 IV From 1600 to 1800 31 V From 1800 to 1900 . 53 VI to From 1900 the End of World War II ... 83 VII Conclusion ................... 96 / CHRONOLOGICAL TABLE. ................. 100 BIBLIOGRAPHY ....................... 108 BIOGRAPHICAL SKETCH 114 iii LIST OF FIGURES Figure Page 1 A 14 1 B 15 2 40 3 42 4 42 5 55 6 65 7 68 8 78 9 86 10 88 11 92 IV CHAPTER I INTRODUCTION Navigation is the art and the science of conducting a vessel on the water, under the water, or in the air, from one position to another. The problems of navigation are those of direction, distance, and location. Celestial navigation, or observational navigation, is the determination of location by the use of celestial objects.
    [Show full text]
  • Tants and Other Reflecting Instruments ; and on Methods of Directly Determining the Errors in Mirrors and Sun-Shades Used in Reflecting Instruments
    VIII.—On the Advantages to be derived from the Use of Metallic Reflectors for Sex- tants and other Reflecting Instruments ; and on Methods of directly determining the Errors in Mirrors and Sun-Shades used in Reflecting Instruments. By JOHN ADIE, Esq. (Read February 17. 1845.) It has frequently occurred to me that the difficulty experienced by instru- ment-makers, in obtaining for sextants and other similar instruments, reflecting mirrors perfectly parallel in their polished surfaces, and also the greater difficulty of procuring glass perfectly homogeneous in its structure, might be overcome by the use of metallic reflectors. It is well known, that, from the want of perfect parallelism in glass mirrors, there arises an error in the reading of such instruments, inasmuch as the emer- gent ray does not pass out of the glass at the same angle as the incident falls upon it, and that from the want of homogeneousness in the substance, and the unequal refractions caused by the veined structure of the glass. Whether this structure of the glass arises from the process of its manufac- ture, or the want of proper admixture of the component parts, before being ca3t into plates, I am not prepared to say; but in all the plate-glass I have tried, by polishing it on the edges, this structure was observed; so much so, that the plates, on being seen through perpendicularly to the plane of their surface, shewed ob- jects perfectly distinct; while objects, when viewed through the glass at right angles to this plane, were seen with difficulty, distorted and twisted in all direc- tions.
    [Show full text]
  • 18. the INFLUENCE of the ROYAL OBSERVATORY at GREENWICH UPON the DESIGN of 17Th and 18Th CENTURY ANGLE-MEASURING INSTRUMENTS at SEA
    Vistas in Astronomy, 1976, Vol. 20, pp. 123-130. Pergamon Press. Printed in Great Britain 18. THE INFLUENCE OF THE ROYAL OBSERVATORY AT GREENWICH UPON THE DESIGN OF 17th and 18th CENTURY ANGLE-MEASURING INSTRUMENTS AT SEA A. STIMSON National Maritime Museum When Charles II founded his Royal Observatory in Greenwich Park in 1675, position finding at sea was not much advanced on the techniques of 200 years earlier when the Portuguese began the art of ocean navigation. It was possible to find a ship's latitude reasonably easily to within 20 or 30 minutes but the business of finding longitude still seemed an insoluble problem. The answer was thought to lie in the lunar-distance method put forward by Werner in 1514, but for this method to be successful, not only was it necessary for the Moon's position to be predicted to within 1 minute of arc several years in advance, but also the "fixed" stars upon which the method depended had to be observed to a like accuracy. Greenwich Observatory was established with the object of finding a solution to the longitude problem, but of necessity Flamsteed concentrated his early efforts on the accurate observation and plotting of star positions. The alternative means of solving the longitude question was the "meckanick's" answer, a clock that would keep time under seagoing conditions and temperatures. In this way a Standard Time could be carried about with which to compare the ship's local time — the difference in time being the longitude. It is not generally realized that neither of these methods could be of much use to a seaman un- less he were equipped with a sufficiently accurate instrument with which to observe the exacting measurements required.
    [Show full text]