Nautical Charts

Nautical Charts

Author:
G. R. Putnam
Author:
G. R. Putnam
Format:
epub
language:
English

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Author: Putnam, G. R. (George Rockwell), 1865-
Nautical charts
Nautical Charts
SURVEYING STEAMER FATHOMER IN MANILA BAY. (Frontispiece)


NAUTICAL CHARTS

BY
G. R. PUTNAM, M.S.
MEMBER OF THE AMERICAN SOCIETY OF CIVIL ENGINEERS
DIRECTOR OF COAST SURVEYS, PHILIPPINE
ISLANDS, 1900 TO 1906

FIRST EDITION
FIRST THOUSAND

NEW YORK
JOHN WILEY & SONS
London: CHAPMAN & HALL, Limited
1908

Copyright, 1908,
by
G. R. PUTNAM

Stanhope Press
F. H. GILSON COMPANY
BOSTON, U.S.A.


PREFACE

In preparing the material for a lecture on Charts for Columbia University, the writer was impressed with the fact that although nautical charts are mentioned or discussed in many publications, there was not found any one which covered the general subject of their origin, construction, and use. In the countries of the world more than a million copies of such charts are now issued annually. A considerable portion of the human race is interested directly or indirectly, whether as mariners or passengers or shippers, in navigation upon the sea. Aside from supplying a handbook for those who might have a general interest in the subject, it was thought that a discussion of charts might lead to further consideration of the principles governing their construction.
This paper has intentionally been made as non-technical as seemed feasible in treating a somewhat technical subject. The writer is indebted to the Coast and Geodetic Survey for various illustrative material from its archives, and to a number of authors for facts or suggestions. A list is appended of books and papers which have been freely consulted, bearing on this and related subjects.
G. R. P.
Washington, D.C., May 24, 1908.


CONTENTS

PAGE
List of Books or Papers bearing on Nautical Charts and related Subjects vii
Charts and Maps 1
Collection of Information for Charts 31
Preparation of Information for Charts 67
Publication of Charts 84
Correction of Charts 97
Reading and Using Charts 112
Use of Charts in Navigation 124
Publications Supplementing Nautical Charts 154
Index 161

[Pg vi-vii]

LIST OF BOOKS OR PAPERS BEARING ON NAUTICAL CHARTS AND RELATED SUBJECTS

Periplus, an Essay on the Early History of Charts, and Sailing Directions. A. E. Nordenskiöld, Stockholm, 1897.
Maps, their Uses and Construction. G. James Morrison, London, 1902.
Charts and Chart Making. Lieut. John E. Pillsbury, U.S.N., in Proceedings U. S. Naval Institute, 1884.
Principal Facts relating to the Earth’s Magnetism. L. A. Bauer, in U. S. Magnetic Declination Tables, Coast and Geodetic Survey, 1903.
Marine Hydrographic Surveys of the Coasts of the World. G. W. Littlehales, in Report of the Eighth International Geographic Congress, 1904.
Smithsonian Geographical Tables. R. S. Woodward, Washington, 1906.
Admiralty Charts, Abridged list of. Published by J. D. Potter, London, 1907.
Military Topography. Capt. C. B. Hagadorn, U.S.A., West Point, 1907.
Service Hydrographique de la Marine, Paris, 1900.
A Manual of Conventional Symbols in Use on Official Charts. United States Hydrographic Office, Gustave Herrle, 1903.
Hydrographical Surveying. Admiral W. J. L. Wharton, London, 1898.
On the Correction of Charts, Light Lists, and Sailing Directions. Published by J. D. Potter, London, 1904.
Notes Relative to the Use of Charts. D. B. Wainwright, Coast and Geodetic Survey, 1900.

The Law relating to Charts and Sailing Directions. H. Stuart Moore, London, 1904.
Notes bearing on the Navigation of H. M. Ships. Hydrographic Office, London, 1900.
The Relations of Harbors to Modern Shipping. W. H. Wheeler, in Engineering News, September 6, 1906, New York.
Wrinkles in Practical Navigation. Capt. S. T. S. Lecky, London, 1899.
Navigation and Compass Deviations. Commander W. C. P. Muir, U.S.N., Annapolis, 1906.
The Practice of Navigation. Henry Raper, London, 1898.
Lehrbuch der Navigation. Reichs-Marine-Amt, Berlin, 1906.
The Nautical Magazine, London.
Dangers and Ice in the North Atlantic Ocean. Bureau of Navigation, U. S. Navy Department, 1868.
Reported Dangers in the North Pacific Ocean. U. S. Hydrographic Office, 1871.
Pacific Islands, Vol. III, chapter on “Vigias.” British Hydrographic Office, London, 1900.
Harriman Alaska Expedition, Vol. II, Bogoslof, our Newest Volcano, by C. Hart Merriam, New York, 1901.
Expedition to the Aleutian Islands, 1907. T. A. Jaggar, Jr., in The Technology Review, 1907, Boston.
Recent Changes in Level in the Yakutat Bay Region, Alaska, by R. S. Tarr and Lawrence Martin, in Bulletin of the American Geological Society, 1906.
An Index to the Islands of the Pacific Ocean. W. T. Brigham, Honolulu, 1900.
Geography, articles by C. R. Markham, A. R. Clarke, and H. R. Mill in Encyclopædia Britannica.
Development in Dimensions of vessels, Elmer L. Corthell, Tenth International Navigation Congress, 1905.


NAUTICAL CHARTS

CHARTS AND MAPS

Need of maps. Maps are useful and necessary for many purposes. Only by means of a correct map or globe can a clear idea of the geography of a region be given. An attempt to convey the same information by a written description would in comparison be both cumbersome and obscure. Even by passing over an extensive region a man unaided by instruments will obtain only a rather crude notion of the relations, which he could clearly see on a good map. The importance among the human arts of the making of maps is indicated by the references to them in very early historical records, and by the skill in map drawing shown by some of the primitive peoples of to-day. This skill exists particularly among races whose mode of life gives them a wide horizon, as for instance the Eskimos. An interesting instance of this was the case of Joe, an Eskimo guide, who, in 1898, before the surveys of the Yukon delta were made, drew a map of the Yukon mouths with much more complete information than any previously available.
Without attempting to enumerate in detail the special uses for maps, in the broader sense they may be said to be essential for commercial, engineering, military, scientific, educational, and political purposes.

Early geography and map making. The oldest map known is a plan of gold mines in Nubia, drawn on a papyrus. This is of the thirteenth century B.C., and was found in Egypt.
In the earliest historic times men believed the earth to be a flat surface of nearly circular outline, a natural inference for those with limited outlook and communication. Later the idea was introduced of the ocean as a river bounding the earth disk. The spherical theory of the earth was, however, early accepted by learned men, and was demonstrated by Aristotle (384 to 322 B.C.), who used as proofs the earth’s shadow on the moon, and the change in the visibility of the stars in traveling north or south. Crates constructed a terrestrial globe in the second century B.C.
There is no Greek or Latin map extant of earlier date than the time of Ptolemy, but there are references showing that maps were in use. One of the first of such passages in Greek literature is the interesting comment of Herodotus written in the fifth century B.C., “but I laugh when I see many who already have drawn the circuits of the earth, without any right understanding thereof. Thus they draw Oceanus flowing round the earth, which is circular, as though turned by a lathe, and they make Asia equal to Europe.”
A map of the world was drawn by Anaximander, 560 B.C. A hundred years later Democritus drew a map having an oblong shape, and taught that the width of the world from east to west was one and a half times its extent from north to south, a conclusion based on his travels eastward as far as India. This theory, which was for a time accepted, has left an enduring mark in the words longitude and latitude, originally signifying the length and the breadth of the earth.
The first application of astronomy to geography was made by Pytheas, who about 326 B.C. obtained the latitude of Marseilles by an observation of the altitude of the sun. Dicearchus in 310 B.C. determined the first parallel of latitude by noting places where on the same day the sun cast shadows of equal length from pillars of equal height. Eratosthenes (276 to 196 B.C.) was the first to compute the circumference of the earth from observations of the altitude of the sun at Alexandria and at Syene in Upper Egypt and an estimation of the distance between these two places. Ptolemy, a Greek of Alexandria, in the years from 127 to 151 A.D. wrote extensively on geographic subjects, and collected into systematic form all geographic knowledge then existing; he was the greatest geographer of early history.
In the ten centuries which followed, part of the early advance in this science was obscured, and the theory that the earth was a flat disk surrounded by the sea again became prevalent. The voyages of discovery of the middle ages, however, led to a rapid development of geographic knowledge.
The flattening of the spherical earth was not suspected until in 1672 a clock regulated to beat seconds at Paris, when taken to Cayenne near the equator was found to lose two and one-half minutes a day. Newton proved that this was due to the fact that the earth is an oblate spheroid. In 1735 accurate measurements were undertaken to determine the size and shape of the earth. The equatorial diameter has been found to be 7926.6 miles and the polar diameter 7899.6 miles, the difference, or 27 statute miles, being the amount of the flattening at the poles.
The first sailing directions. The early Greek and Roman writers do not allude to charts or maps intended especially for the use of seafarers. There are, however, extant several peripli or descriptions of the coast. Some of these appear certainly to have been intended for use as nautical guides, corresponding to the modern sailing directions. It is probable that they were explanatory of or accompanied by coast charts, now lost. They are of interest therefore as being probably the first compilations for the guidance of seamen. One of the earliest, written apparently in the fifth and fourth centuries B.C., is entitled “Scylax of Caryanda, his circumnavigation of the sea of the inhabited part of Europe and Asia and Libya.” It contains a systematic description of the coasts of the Mediterranean, Black Sea, and part of the west coast of Africa. The following are some extracts which indicate the character of the work. It is to be noted that no bearings are given, and that distances are usually stated by day’s sail: Africa is referred to as Libya.
“Europe. I shall begin from the Pillars of Hercules in Europe and continue to the Pillars of Hercules in Libya, and as far as the land of the great Ethiopians. The Pillars of Hercules are opposite each other, and are distant from each other by one day’s sail…. From Thonis the voyage to Pharos, a desert island (good harborage but no drinking water), is 150 stadia. In Pharos are many harbors. But ships water at the Marian mere, for it is drinkable…. From Chersonesus is one day’s sail; but from Naustathmus to the harbor of Cyrene, 100 stadia. But from the harbor to Cyrene, 80 stadia; for Cyrene is inland. These harbors are always fit for putting into. And there are other refuges at little islands, and anchorages and many beaches, in the district between…. After the isthmus is Carthage, a city of the Phœnicians, and a harbor. Sailing along from Hermæa it is half a day to Carthage. There are islands off the Hermæan cape, Pontia island and Cosyrus. From Hermæa to Cosyrus is a day’s sail. Beyond the Hermæan cape, towards the rising sun, are three islands belonging to this shore, inhabited by Carthaginians; the city and harbor of Melite, the city of Gaulus, and Lampas; this has two or three towers…. The sailing along Libya from the Canopic mouth in Egypt to the Pillars of Hercules … takes 74 days if one coast round the bays…. From the cape of Hermæa extend great reefs, that is, from Libya towards Europe, not rising above the sea; it washes over them at times…. From Thymiateria one sails to cape Soloes, which juts far into the sea. But all this district of Libya is very famous and very sacred…. This whole coasting from the Pillars of Hercules to Cerne Island takes twelve days. The parts beyond the isle of Cerne are no longer navigable because of shoals, mud, and sea-weed. This sea-weed has the width of a palm, and is sharp towards the points, so as to prick.”
That there were many other similar writings in the following centuries is shown by the following quotation from Marcianus, in a preface to sailing directions written in the fifth century A.D.: “This I write after having gone through many sailing directions, and spent much time on their examination. For it behooves all who are men of education, to scrutinise such attempts at learning in this subject, so as neither rashly to believe the things that are said, nor incredulously to set their private opinions against the careful decisions of others.”
The oldest extant sailing directions of the middle ages bear date 1306 to 1320.
Development of chart making. The application of the compass to nautical use in the twelfth century A.D. had a marked effect in encouraging voyages of exploration, and therefore indirectly on chart making. The following, written toward the close of the twelfth century, is the first known mention of the use of the compass in Europe: “The sailors, moreover, as they sail over the sea, when in cloudy weather they cannot longer profit by the light of the sun, or when the world is wrapped in the darkness of the shades of night, and they are ignorant to what part of the horizon the prow is directed, place the needle over the magnet, which is whirled round in a circle, until, when the motion ceases, the point of it (the needle) looks to the north.” The nautical compass of that time appears to have consisted of a magnetized needle, floated in a vessel of water by a cork or reed, and having no index nor compass card. Peregrinus in 1269 made notable improvements in the compass, including a pivot suspension for the needle, a graduation, a lubber line, and an azimuth bar for sighting on the sun or other object.
Nautical charts are known to have been in use since the thirteenth century A.D., but the earliest extant of which the date can be fixed is Vesconte’s loxodromic chart of 1311.

The loxodromic charts first appeared in Italy, and were so called from the fact that they were crossed by loxodromes (or rhumb lines) radiating from a number of crossing points distributed regularly over the map. Compass roses carefully drawn were later added at these crossing points, the first appearing on a chart of 1375. The earliest known mention of the variation of the compass from true north was on the first voyage of Columbus, who discovered this important fact in 1492, and as a consequence his “seamen were terrified and dismayed.” Before that time it was assumed in Europe that the compass pointed “true to the north pole.” The apparent failure to detect the variation earlier was doubtless to some extent due to its small amount at that time along the Mediterranean. The earlier charts showed both lines and compass roses apparently oriented with the true meridian, though there is some evidence to indicate that they were actually oriented with the magnetic meridian, the designer not recognizing any difference. The variation of the compass was first marked on a map in 1532 and on a printed chart in 1595, but the placing of magnetic compasses on charts did not become customary until about fifty years ago. These early charts were drawn on parchment, using bright colors. They were copied by hand, one from another, with gradual variations. They had no projections, and the draftsmen evidently had no idea of the sphericity of the earth. Islands and points were usually exaggerated; shallows were indicated, but no soundings; no information was given as to the interior of the countries; a scale of distances was nearly always provided.

Charts were first printed about 1477, and are known to have been engraved on copper by 1560.
The maps of Ptolemy were ruled with degree lines, but no chart was so provided until 1427; by 1500, however, most charts were graduated. Before this date it is not known on what projection the charts were constructed. On the first graduated charts the degree lines were equidistant parallel straight lines cutting each other at right angles and thus dividing the chart into equal squares or rectangles. These were known as “plain charts.” This square projection had little to commend it save simplicity of construction, as in higher latitudes it gave neither directions nor distances correctly. The difficulties of its use in navigation were early recognized, and nautical works contained chapters on “sailing by the plain chart, and the uncertainties thereof.”
The example of early chart making shown in Fig. 2 is of great interest as being the earliest extant chart which includes America. This chart was drawn on ox-hide in 1500 by Juan de la Cosa, who accompanied Columbus on his first voyage as master of his flagship, and on his second voyage as cartographer. The chart, of which only a portion is shown here, purports to cover the entire world; it joins Asia and America as one continent, the Pacific Ocean being then still unknown.

FIG. 2. CHART OF NORTH ATLANTIC OCEAN, BY JUAN DE LA COSA, 1500. EARLIEST EXTANT CHART SHOWING AMERICA.
Fig. 2 enlarged (652 kB)

Gerhard Krämer, a Flemish map-maker, better known by his Latin name of Mercator, in 1569 published his famous Universal Map. In this map the meridians and parallels were still straight lines intersecting at right angles, but the distances between the parallels were increased with increasing latitude in such proportion that a rhumb line, or line cutting the meridians at a constant angle, would appear on the map as a straight line. Mercator never explained the construction of his chart, and as the above condition was not accurately carried out, it is thought that the chart was drawn by comparing a terrestrial globe with a “plain chart.” After examination of a mercator chart in 1590, Edward Wright developed the correct principles on which such a chart should be constructed, and published in 1599 his treatise “The Correction of Certain Errors in Navigation.” It took nearly a century to bring this chart into use, and even in the middle of the eighteenth century nautical writers complain that “some prefer the plain chart.”
The Arcano del Mare, 1646, was the first marine atlas in which all the m

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