MAGNETIC VARIATION. 143 



to advance southward from the basin of the Caspian Sea ; 

 or whether, as Erman maintains, it may not curve to the 

 eastward, and, rising between Borneo and Malacca, reach 

 the Sea of Japan,* and penetrate into Eastern Asia through 

 the Gulf of Ochotsk. It is much to be lamented that, not- 

 withstanding the frequent voyages made to and from India, 

 Australia, the Philippines, and the northeast coasts of Asia, 

 a vast accumulation of materials should remain buried and 

 unheeded in various ships' logs, which might otherwise lead 

 to general views, by which we might be enabled to connect 

 Southern Asia with the more thoroughly explored parts of 

 Northern Asia, and thus to solve questions which were start- 

 ed as early as 1840. In order, therefore, not to blend to- 

 gether known facts with uncertain hypotheses, I will limit 

 myself to the consideration of the Siberian portion of the 

 Asiatic continent, as far as it has been explored in a souther- 

 ly direction to the parallel of 45° by Erman, Hansteen, Due, 

 KupfFer, Fuss, and myself. In no other part of the earth 

 has so extended a range of magnetic lines been accessible to 

 us in continental regions; and the importance which Euro- 

 pean and Asiatic Russia presents in this respect was ingen- 

 iously conjectured even before the time of Leibnitz.f 



upon my own declination observations in the Caspian Sea, at Uralsk 

 on the Jaik, and in the Steppe of Elton Lake (Asie Centrale, t. hi., p. 

 45S-461). 



* Adolf Erman's Map of the Magnetic Declination, 1S27-1830. 

 Elliot's chart shows, however, most distinctly that the Australian curve 

 of no variation does not intersect Java, but runs parallel with, and at 

 a distance of 1° 30' latitude from the southern coast. Since, accord- 

 ing to Erman, although not according to Gauss, the Australian line 

 of no variation between Malacca and Borneo enters the Continent 

 through the Japanese Sea, proceeding to the closed oval group of 

 Eastern Asia, on the northern coast of the Sea of Ochotsk (59° 30' 

 N. lat.), and again descends through Malacca, the ascending line can 

 only be 11° distant from the descending curve; and according to this 

 graphical representation, the Western Asiatic line of no variation 

 (from the Caspian Sea to Russian Lapland) would be the shortest and 

 most direct prolongation of the part descending from north to south. 



f I drew attention as early as 1843 to the fact, which I had ascer- 

 tained from documents preserved in the Archives of Moscow and 

 Hanover {Asie Centrale, t. iii., p. 469-476), that Leibnitz, who con- 

 structed the first plan of a French expedition to Egypt, was also the 

 first who endeavored to profit by the relations which the czar, Peter 

 the Great, had established with Germany in 1712, by using his influ- 

 ence to secure the prosecution of observations for '"determining the 

 position of the lines of variation and inclination, and for insuring that 

 these observations should be repeated at certain definite epochs" in 

 different parts of the Russian empire, whose superficies exceed those 



