426 



NA rURE 



[September 3, 1891 



The eminent position which Italian cartographers occupied 

 during the fourteenth and fifteenih centuries had to be sur- 

 rendered by them, in the beginning of the sixteenth, to their 

 :pupils, the Portuguese and Spaniards, upon whom extensive 

 voyages and discoveries had conferred exceptional advantages. 

 These, in turn, had to yield to the Germans, and later on to the 

 Dutch, who were specially qualified to become the reformers 

 -of cartography by their study of mathematics and of the ancient 

 geographers, as also by the high degree of perfection which the 

 arts of engraving on wood and copper had attained among them. 

 German mathematicians first ventured to introduce the long- 

 neglected geographical projections of Hipparchus and Ptolemy, 

 and devised others of their own. Werner of Niirnberg (1514) 

 invented an equivalent heart-shaped projection, whilst both 

 Apianus and Staben (1520 and 1522) suggested equivalent pro- 

 jections. Still greater were the services of Gerhard Cremer, or 

 Mercator (1512-94), the Ptolemy of the sixteenth century, who 

 not only introduced the secant conical projection, but also in- 

 vented that still known by his name, which was calculated to 

 j'ender such great service to the navigator, but was nevertheless 

 not universally accepted until the middle of the fifteenth century, 

 ■when the mediaeval compass and plane charts finally dis- 

 appeared. 



The German cartographers of that age are to be commended, 

 not because they copied Ptolemy's maps — for in this they had 

 been preceded by others — but because they adopted his scientific 

 methods in producing maps of their own. Their reforms began 

 at home, as all reforms should. They were amply supported in 

 their efforts by the many astronomers of note of whom Germany 

 then boasted, and by quite a staff of local "geographers," of 

 whom nearly every district of the empire boasted the possession 

 of one. Among these local maps, that of Bavaria, by Philipp 

 Bienewitz, or Apianus (1566), holds a distinguished rank, for it 

 is the first map on a large scale (i : 144,000) based upon a 

 regular survey. Its errors in latitude do not exceed 1', and 

 those in longitude 3', which is marvellously correct considering 

 the age of its production. Like most maps of the period, it is 

 engraved on wood, for though the art of engraving on copper 

 was invented in Germany before 1446, and the first map was 

 engraved there in 1450, copper engraving only became general 

 at a much later date. 



Perhaps the earliest general map of Germany, and certainly 

 one of the most interesting, was that which the famous Cardinal 

 Nicolas of Cues or Cusa completed in 1464, the only existing 

 copy of which is to be found in the British Museum, where it 

 was "discovered" by Baron Nordenskiold. Mercator's map of 

 Germany, published more than a century after that of the learned 

 Cardinal (in 1585), was naturally far more complete in all re- 

 spects, and was certainly far superior to the maps of any other 

 country existing at that time. This fact is brought home to us 

 by an inspection of a collection of maps to be found in the well- 

 known 'Theatrum Orbis" of Ortelius (first published in 1570), 

 where we may see that the maps supplied by Humphrey Lloyd 

 and other British cartographers are still without degree lines. 



But when we follow Mercator, or, in fact, any other carto- 

 grapher of the period, into regions the successful delineation of 

 which depended upon an intelligent interpretation of itineraries 

 and of other information collected by travellers, they are found to 

 fail utterly. Nowhere is this utter absence of the critical faculty 

 more glaringly exhibited than in the maps of Africa of that 

 period. 



Among the Dutch cartographers of that age one of the fore- 

 most places must be accorded to Waghenaer of Enkhuisen, 

 whose "Mirror of the Sea," a collection of charts published in 

 1583, enjoyed a considerable reputation among British seamen. 

 Other famous Dutch publishers of charts were Ortelius, Janssen, 

 Blaeuw, and Vischer, who accumulated large stocks of copper 

 plates, which constituted valuable heirlooms, and, not unlike 

 the plates of certain modern map-publishers, supplied edition 

 after edition without undergoing any change, except perhaps 

 that of the date. 



The age of great discoveries was past. All blanks upon our 

 maps had not yet been filled up, but the contours of the great 

 continents stood out distinctly, and in the main correctly. Dis- 

 coveries on a large scale had become impossible, except in the 

 Polar regions and in the interior of some of the continents ; but 

 greater preciseness had to be given ito the work already done, 

 and many details remained to be filled in. In this "age of 

 measurements," as Peschel significantly calls it, belter instru- 



NO. II 40, VOL. 44] 



merts, and methods of obseivation superior to those which had 

 sufficed hitherto, vieie needed, and were readily forthcoming. 



I'icard, by making use of the telescope in neasuring angles 

 (1667), obtained results of a degree of accuracy formerly quite 

 unattainable, even with instruments of huge proportions. For 

 the theodolite, that mo^t generally useful surveying instrument, 

 we are indebted to Jonathan Sission (1737 or earlier). More 

 important still, at all events to the mariner, was the invention of 

 the sextant, generally ascribed to Hadley (1731), but in reality 

 due to the genius of Newton. Equally important was the pro- 

 duction of a trustworthy chronometer by John Harrison (1761), 

 which first made possible the determination of meridian distances, 

 and is invaluable w henever a correct knowledge of the time is 

 required. One other instrument, quite recently added to the 

 apparatus of the surveyor, is the photographic camera, converted 

 for his especial benefit into a photogrammeter. This instrument 

 1 as not as yet been utilized for ascertaining the relative positions 

 of celestial bodies, but has already done excellent service in 

 ordinary surveying, especially when it is required to portray the 

 sides of inaccessible mountains. 



But the full fruits of these inventions could be enjoyed only 

 after Bradley had discovered the aberration of light (1728) and 

 the nutation of the earth's axis (1747) ; Domenique Cassini had 

 furnished trustworthy tables of the refraction of light ; and the 

 complicated movement of the moon had been computed by Euler 

 (1746), Tobias Mayer (1753), Bradley (1770), and, more recently, 

 by Hansen. 



Positively novel methods for determining the latitude and longi- 

 tude of a place can scarcely be said to have been proposed 

 during thi-; period, but many of the older methods only became 

 really available afier the improvements in the ins'ruments indi- 

 cated above had taken place, and the computations had been 

 freed from the errors which vitiated them formeily. 



Real progress, however, has been made in the determination 

 of altitudes. Formerly they could be ascertained only by trigono- 

 metrical measurement, or by a laborious process of levelling, 

 but since physicists have shown how the decrease of atmospheric 

 pressure with the altitude, and the boiling-point ofwater depend- 

 ing upon this decrease, afforded a ready means of determining 

 heights, the barometer, aneroid, and boiling-point thermometer 

 have become the indispensable companions of the explorer, and 

 our knowledge of the relief of the land has advanced rapidly. 



Equally rapid have been the improvements in our instruments 

 for measuring the depth of the ocean, since a knowledge of the 

 configuration of its bed was demanded by the practical require- 

 ments of the telegraph engineers. 



And in proportion as the labours of the surveyors and ex- 

 plorers gained in preciseness, so did the cartographer of the age 

 succeed in presenting the results achieved in a manner far more 

 satisfactory than had been done by his predecessor-. His ta-k 

 was comparatively easy so long as he only dealt with horizontal 

 dimensions, though even in the representation of these a certain 

 amount of skill and judgment are required to make each feature 

 tell in proportion to its relative importance. The delineation of 

 the inequalities of the earth's surface, however, presented far 

 greater difficulties. The mole-hills or serrated ridges, which 

 had not yet quite disappeared from our maps in the beginning of 

 this century, failed altogether in doing justice to our actual 

 knowledge. The first timid attempt to represent hills as seen 

 from a bird's-eye view, and of shading them according to the 

 steepness of their slopes, appear on a map of the Brei-gau^ pub- 

 lished by Homarin in 1718. We find this system fully developed 

 on La Condamine's map of Quito, published in 1751, and it was 

 subsequently popularized by Arrowsmith. In this crude system 

 of hill shading, however, everything was left to the judgment of 

 the draughtsman, and only after Lehmann (1783) had super- 

 imposed it upon a groundwork of contours, and had regulated 

 the strength of the hatching in accordance with the degree of 

 declivity to be represented did it become capable of conveying a 

 correct idea of the configuration of the ground. 



The first to fully recognize the great importance of contours 

 was Philip Buache, who had prepared a contoured map of the 

 Channel in 1737, and suggested that the same system might 

 profitably be extended to a delineation of the relief of the land ; 

 and this idea, subsequently taken up by Ducarla of Vabres, was 

 for the first time carried into practice by Dupain-Triel, who pub- 

 lished a contoured map of France in 1791. Up to the present 

 time more than eighty methods of showing the hills have been 

 advocated, but it may safely be asserted that none of these 



