70 COSMOS. 



1829. KupfFer, Voyage au Mont Elbrouz dans le Caucase, 

 p. 68-115. 



1829. Humboldt's magnetic 'observations on terrestrial 

 magnetism, with the simultaneous astronomical determina- 

 tions of position in an expedition in Northern Asia, under- 

 taken by command of the Emperor Nicholas, between the 

 longitudes 11° 3' and 80° 12' east of Paris, near the Lake 

 Dzaisan, as well as between the latitudes of 45° 43' (the 

 island of Birutschicassa, in the Caspian Sea) to 58° 52', in 

 the northern parts of the Ural district, near Werchoturie 

 (Asie Centrale, t. iii., p. 440-478). 



1829. The Imperial Academy of Sciences at St. Peters- 

 burg acceded to Humboldt's suggestion for the establish- 

 ment of magnetic and meteorological stations in the different 

 climatic zones of European and Asiatic Russia, as well as 

 for the erection of a physical central observatory in the capi- 

 tal of the empire under the efficient scientific direction of 

 Professor Kupffer. (See Cosmos, vol. i., p. 190. KupfFer, 

 Rapport Adresse a V Acad, de St. Pctersbourg relatif a VObser- 

 vatoire physique central, fonde aupres da Corps des Alines, in 

 Schum., Astr. JSfachr., No. 72G ; and in his Annates Magne- 

 tiqnes, p. xi.) Through the continued patronage which the 

 Finance Minister, Count Cancrin, has awarded to every 

 great scientific undertaking, a portion of the simultaneously 

 corresponding observations* between the White Sea and the 



* The first idea of the utility of a systematic and simultaneously 

 conducted series of magnetic observations is due to Celsius, and, with- 

 out referring to the discovery and measurement of the influence of 

 polar light on magnetic variation, which was, in fact, due to his as- 

 sistant, Olav Hiorter (March, 1741), we may mention that he was the 

 means of inducing Graham, in the summer of 1711, to join him in his 

 investigations for discovering whether certain extraordinary perturba- 

 tions, which had from time to time exerted a horary influence on the 

 course of the magnetic needle at Upsala, had also been observed at 

 the same time by him in London. A simultaneity in the perturba- 

 tions afforded a proof, he said, that the cause of these disturbances is 

 extended over considerable portions of the earth's surface, and is not 

 dependent upon accidental local actions (Celsius, in Svenska Veten- 

 skaps Academicns Handlingar for 1740, p. 44; Hiorter, op. cit., 1747, 

 p. 27). As Arago had recognized that the magnetic perturbations, 

 owing to polar light, are diffused over districts in which the phenom- 

 ena of light which accompany magnetic storms have not been seen, 

 he devised a plan by which he was enabled to carry on simultaneous 

 horary observations (in 1823) with our common friend Kupffer at 

 Kasan, which lies almost 47° east of Paris. Similar simultaneous ob- 

 servations of declination were begun in 1828 by myself, in conjunction 

 with Arago and Reich, at Berlin, Paris, and Freiberg (see Poggend., 

 Annaleiiy bd. xix., s. 337). 



