NOTES.
La Carte de France, dite de l'Etat Major, par M. J. Collet. Paris, 1887. 8vo, pp. 92, with 4 plates.—This pamphlet describes the great "Staff Map" of France, recently completed, giving its history, the methods employed in the field and office work, the contents of the map, and the means of representing the various features therein described. The scale of the map is 1:80,000. Relief is represented by hachures, for drawing which approximate contour lines have been located, but these are not otherwise used. A great variety of cultural features are shown, many of which are ephemeral, and which contribute to the overloading of the map with details. Moreover, as the time which has ordinarily elapsed between the survey and the issuance of the work in printed form is ten or twelve years, most of this culture has become not only of no value but misleading by the time it is published.
The account of the organization and methods by which the map has been produced is of special interest. The primary triangulation upon which it is based is one of the most elaborate and accurate ever executed in any country. No expense has been spared in this direction. Within this triangulation is a secondary triangulation, also very elaborate, from the stations of which numerous additional points are cut in, or located by unclosed triangles. All this work is of the highest order of excellence, being infinitely more accurate than the map requires. With this, however, the accuracy appears to end. The detail consists of the map, or the map proper, little more than a compilation of commune cadastral plans. These were fitted to the triangulation points and to one another, a process which appears to have been by no means easy of satisfactory accomplishment. This adjustment having been completed, the culture was brought up to date of survey and a survey was made of the relief features by the use of such inferior instruments as the clinometer compass and chain.
The principal and obvious criticism upon such work is that it is top-heavy. The triangulation is far more elaborate than is required, while the provision for making the map itself is by no means comparable with it: it is as far below the requirements of the scale as the triangulation is above it.
This leads up to a broader proposition, which may be stated thus: That the general tendency of surveying organizations is in the direction illustrated by that of the "French Staff." Organized originally for map-making, they progress little by little in the direction of devoting their energies to geodetic work, while at the same time the topographic work proper, for which they were created, is belittled and neglected. As a consequence the latter depreciates in quality and diminishes in quantity; the main purpose of the organization is lost, and a mere means becomes the ultimate end of the work. This tendency should be recognized in map-making organizations. The weakness of our modern maps is seldom in the primary control. It is easy to do triangulation of sufficient accuracy for the control of maps upon such scales as that above considered, little knowledge or experience being required beyond that gained at our engineering schools; while the more accurate triangulation, generally known as geodetic work, requires merely better instruments, more time, and more experienced observers.
The weak features of maps are generally the details, the part of the work that, strange to say, is usually relegated to the lowest grade of professional men. This weakness consists in an insufficiency of minor locations for the control of the sketch and in unfaithful sketching. It is the sketching that requires the most careful attention and the best and most experienced men. The instrumental portion of the work is the least difficult; the artistic portion, or sketching, is the most difficult. It would seem more logical and would doubtless produce better results to reverse the usual order of promotion and place the topographer above the triangulator. Moreover, the triangulation should be regarded as merely a means for the correction of the sketching, and it should be required only that it be of sufficiently high grade to meet this condition. The minor locations should be sufficiently numerous and well distributed to fully control and correct the sketching; and finally the sketching should be as faithful a representation of the topography as is consistent with the necessary generalization of the surface features.
H. G.
Polar Regions.—The Societe de Geographie of Paris in its Proceedings publishes the following communication from M. Ch. Rabot on the new Danish expedition engaged in the exploration of the eastern coast of Greenland, under the command of Lieutenant Ryder, of the royal Danish navy. The expedition has in view the examination of the unknown coast between Franz-Josef fiord, in latitude 73°, and the most northerly point reached by Commander Holm and Lieutenant Garde, about latitude 66°. Lieutenant Ryder left Copenhagen June 7, 1891, in the Norwegian whaler Hekla, which had been chartered by the Danish government. The first ice was met on the 20th, in latitude 68° 12', longitude 13° 05' west. Unable to pass through the pack to the Greenland shore after several attempts, the ship proceeded northward, and in the vicinity of Jan Mayen made soundings and successful dredgings. Several attempts to reach the coast of Greenland were made from the 75th parallel southward, but without success up to July 2, when the Hekla was in latitude 71° 31', longitude 6° 30' west. Since that date there has been no direct news, but on July 26, in latitude 72° 40', longitude 14° 25' west, the English whaler Active saw the Hekla a few miles to the northeast, heading to the south-southwest. On August 2 the Active, in latitude 71° 40', approached within 12 miles of the coast, and on August 20, in 70° 30', was within 7 miles of the mainland. In both instances the intervening sea was free of ice. The English captain believes that the Hekla made the eastern coast in about 71° 30'. The Hekla is provisioned for the winter, and there is a prospect of marked success by the Danish officers in their undertaking.