June 25, I860.] ADDITIONAL NOTICES. 243 



with descriptions, &c.— Growe, N. Vibe, and Aubert, Southern Norway, 7 sheets; 

 A. Vibe, ditto, 6 sheets; Schie, ditto, 4 sheets; A. Vibe, Northern Norway, 12 

 sheets. Total, 45 sheets. 



11. Of the above mentioned later maps, and especially of the charts of the 

 coast, many have been published in new and corrected editions. Altogether 

 a number of 20,100 copies have been sold ; viz., 3540 maps of districts, 1100 

 maps by Munch, and 15,460 charts of the coast ; and in the oflSce are still in 

 store about 12,000 copies. 



12. The fishing-banks and the " Sea-bridge " have been surveyed, and the 

 manuscript records, accompanied by illustrating charts, are preserved in the 

 archives of the office. 



13. The measurement of degrees in Finmark is completed, and its results 

 published. 



14. The results of the chronometric expedition have likewise been published. 

 During late years the office has received a very considerable collection of 

 printed foreign charts, especially hydrographical. These have chiefly been 

 presented by Government, or by the Geographical Societies of Sweden, Den- 

 mark, England, Russia, France, the United States of America, &c. 



3. The Federal Map of Switzerland. Communicated, by Prof. Paul 

 Chaix of Geneva, Corresponding Member r.g.s. 



The origin of this great work is due to the triangulation of the western part 

 of Switzerland, undertaken at the end of last century, by M. Tralles, of Berne, 

 for the special purpose of determining systematic laws of refraction from the 

 different altitudes of the mountain summits. About the same time M. Feer, 

 the astronomer at Zilrich, with the assistance of M. Pestalozzi, drew from a 

 base line measured on the banks of the river Sihl, near Zurich, a series of 

 triangles to the shores of the Lake of Constance ; a great number of their signal 

 stations have, however, been destroyed, and there are no means of finding their 

 sites. In 1811 Professor Trechsel was commissioned by the Government of 

 Berne to triangulate the southern part of that canton, resting upon the base 

 measured at Aarberg by M. Tralles. This work was completed in 1816, and 

 has been revised and embodied in the general triangulation of Switzerland. In 

 1822 a survey of part of the district of Sargans on the eastern frontier was 

 made and submitted to the Federal Government, which was then deliberating 

 upon the execution of the great topographical map of the Confederation. The 

 work having been decided upon, its execution was entrusted to Quartermaster- 

 general Finsler, who preserved the general management till 1828, when he 

 was succeeded by General Wiirstenberg, who carried it on till 1833, being in 

 his turn succeeded by Colonel, now General Dufour, by whom it is now being 

 completed. 



The map is designed on the scale of Wdm of nature, constructed on 

 Flamsteed's modified projection, and to be completed in twenty-five sheets, 

 each sheet being seventy centimetres long and forty-eight centimetres broad, 

 corresponding to an area of 70,000 metres by 48,000. 



Two base lines were measured by M. Tralles, with the assistance of M. 

 Hassle, of Aarau, one near Aarberg, and the other near Thoune ; the former 

 was measured twice, once in 1791 and again in 1797, both measurements 

 giving a length of 40,188"5 French feet, and differing from each other by only 

 one-fifth of a foot. In 1832 it was remeasured, owing to a difference of gg^gg 

 being discovered between the sides of triangles connected with it from a short 

 base measured by M. Feer, near ZUrich ; this difference was found to be due to 



VOL. IV. T 



