Page:EB1911 - Volume 17.djvu/667

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MAP
[TOPOGRAPHICAL SURVEYS

contours are based upon instrumental measurement, and as a whole these ordnance maps were undoubtedly superior in accuracy, with rare exceptions, to similar maps published by foreign governments. Even though the hill hachures on the older one-inch maps are not quite satisfactory, this deficiency is in a large measure compensated for by the presence of absolutely trustworthy contours. Originally the maps were engraved on copper, and the progress of publication was slow; but since the introduction of modern processes, such as electrotyping (in 1840), photography (in 1855) and zincography (in 1859), it has been rapid. A plan, the engraving of which formerly took two years, can now be produced in two days.

The one-inch map for the whole of the United Kingdom was completed in 1890. It covers 697 sheets (or 488 of a “new series” in large sheets), and is published in three editions, viz. (a) in outline, with contours in black, (b) with hills hachured in brown or black, and (c) printed in five colours. Carefully revised editions of these and of the other maps are brought out at intervals of 15 years at most. Since 1898 the department has also published maps on a smaller scale, viz. a map of England and Wales, on a scale of 2 m. to 1 in., in two editions, both printed in colour, the one with hills stippled in brown, the other coloured on the “layer system” as a strata-relief map; a map of the United Kingdom on a scale of 4 m. to 1 in., also in two editions, the one in outline, showing five classes of roads and parish boundaries, the other in colours, with stippled hills; a map on a scale of 10 m. to 1 in., also in two editions, and finally a map of the United Kingdom on a scale of 1 : 1,000,000.

The geological surveys of Great Britain and Ireland were connected from 1832 to 1853 with the ordnance survey, but are now carried on independently. The ordnance survey, too, no longer depends on the war office but upon the board of agriculture and fisheries. A Bathymetrical Survey of the Freshwater Lochs of Scotland, under the direction of Sir John Murray and L. Pullar, was completed in 1908, and the results published by the Royal Geographical Society.

Proposals for a new map of France, to replace the famous Cassini map of 1744–1793 were made in 1802 and again by R. Bonne in 1808, but owing to the wars then devastating Europe no steps were taken until 1817, and the Carte de France de l’état major on a scale of 1 : 80,000 was France. only completed in 1880. It is engraved on copper. The hachured hills are based upon contours, and are of admirable commensurability. It has served as a basis for a Carte de la France, published by the Service Vicinal on a scale of 1 : 100,000, in 596 sheets, and of a general map prepared by the ministère des travaux publics on a scale of 1 : 200,000 in 80 sheets. On both these maps the hills are printed in grey chalk. A third topographical map of France is being published in accordance with the recommendation of a committee presided over by General de la Noix in 1897. The surveys for this map were begun in 1905. The maps are based upon the cadastral plans (1 : 1000), thoroughly revised and connected with the triangulation of France and furnished with contours at intervals of 5 m. by precise measurement. These minutes are published on a scale of 1 : 10,000 or 1 : 20,000 for mountain districts, while the scale of the general map is 1 : 50,000. Each sheet is bounded by parallels and meridians. The hills are shown in brown contours at intervals of 10 m. and grey shading in chalk (Berthaut, La Carte de France, 1750–1898; Paris, 1899). A geological map of France on a scale of 1 : 80,000 is nearly completed, there are also a map (1 : 500,000) by Carez and Vasseur, and an official Carte géologique (1 : 1,000,000; 1906).

By the middle of the 19th century topographical maps of the various German states had been completed, and in several instances surveys of a more exact nature had been completed or begun, when in 1878 the governments of Prussia, Saxony, Bavaria and Württemberg agreed to supersede Germany. local maps by publishing a map of the empire (Reichskarte) in 674 sheets on a scale of 1 : 100,000. The earlier sheets of this excellent map were lithographed, but these are gradually being superseded by maps engraved on copper. Colour-printing is employed since 1901. The hills are hachured and in some instances contours at intervals of 50 metres are introduced. The map was completed in 1909, but is continually undergoing renewal. The Messtischblätter, called Positionsblätter in Bavaria, are on a scale of 1 : 25,000. The older among them leave much to be desired, but those of a later date are satisfactory. This applies more especially to the maps of Saxony (since 1879) and Württemberg (since 1893). The features of the ground on most of these maps are shown by contours at intervals of 10 metres. The map produced on this large scale numbers over 5000 sheets, and is used as a basis for the geological surveys carried on in several of the states of Germany. A general map of the German Empire (Uebersichtskarte) on a scale of 1 : 200,000, in 196 sheets, is in progress since 1893. It is printed in three colours, and gives contours at intervals of 10 metres. In addition to these maps there are D. G. Reymann’s well-known Specialkarte von Mittel Europa (1 : 200,000), acquired by the Prussian government in 1874 (it will ultimately consist of 796 sheets), a government and Liebenow’s map of central Europe (1 : 300,000) and C. Vogel’s beautiful map of Germany (1 : 500,000).

The Specialkarte of Austria-Hungary on a scale of 1 : 75,000 (765 sheets), based upon a triangulation and cadastral surveys (1816–1867), was completed in 1889, and published in heliogravure. This map was repeatedly revised, but as it no longer met modern requirements as to Austria-Hungary. accuracy the director of the military geographical establishment at Vienna, Field Marshal Chr. von Steeb, in 1896, organized what practically amounts to a re-survey of the entire monarchy, to be completed in 75 years. At the same time the cadastral plans, reduced to a scale of 1 : 25,000, are being published in photo-lithography. A general map of central Europe in 283 sheets published by the Austrian government (1 : 200,000) includes nearly the whole of the Balkan Peninsula.

The famous map of Switzerland, with which is associated the name of General H. Dufour (d. 1875), is based upon a triangulation (1809–1833) and surveys on a scale of 1 : 25,000 for the lowlands, 1 : 50,000 for the alpine districts, and was published (1842–1865) on a scale of 1 : 100,000. Switzerland. The hills are hachured, the light, in the case of the loftier regions, being supposed to fall obliquely. The original surveys, carefully revised, have been published since 1870 as a Topographical Atlas of Switzerland—the so-called Siegfried Atlas, in 552 sheets. They are printed in three colours, contours at intervals of 10 and 20 metres being in brown, incidental features (ravines, cliffs, glaciers) in black or blue. To mountain-climbers these contour maps are invaluable, but for ordinary purposes “strata maps,” such as J. M. Ziegler’s hypsometric maps (1856) or so-called “relief maps,” which attempt to delineate the ground so as to give the impression of a relief, are generally preferred.

The new survey of Belgium was completed in 1872 and there have been published 527 plane-table sections or planchettes on a scale of 1 : 20,000 (1866–1880), a “Carte topographique de la Belgique,” in 72 sheets, on a scale of 1 : 40,000 (1861–1883), and a more recent map in 26 sheets Belgium. on a scale of 1 : 100,000 (1903–1912). The last is printed in five colours, the ground is shown in contours of 10 metres interval and grey stippling.

The new survey of the Netherlands, based upon General Krayenhoff’s primary triangulation (1802–1811) was completed in 1855. The results have been published on a scale of 1 : 25,000 (776 sheets, since 1866), 1 : 50,000 (Topographic and Military Map, 62 sheets, 1850–1864, and a Holland. Waterstaatskaart, 1864–1892), and 1 : 200,000 (Topographical Atlas, 21 sheets, 1868–1871).

In Denmark, on the proposal of the Academy of Science, a survey was carried out in 1766–1825, but the maps issued by the Danish general staff depend upon more recent surveys. These include plane-table sections (Maalebordsblade), 1209 sheets on a scale of 1 : 20,000, with contours Denmark. at intervals of 5 to 10 ft., published since 1830; Atlasblade