284 PROCEEDINGS OF THE AMERICAN ACADEMY 



liberality of the Norwegian government, he was able himself to make 

 a journey to Siberia, in company with Due and Erman, themselves 

 zealous devotees in the same cause. They left the gate of Berlin, in 

 search of an ideal point in a strange region, on April 25, 1828, and 

 penetrated as far as to Kiachta and L'kutsk. The Russian government 

 offered every facility and encouragement to the undertaking. If Han- 

 steen's journey was less of a pageant and an ovation than that which 

 Humboldt made in 1829, by command of the Emperor of Russia, 

 nevertheless it yielded an abundant harvest in the fields of terrestrial 

 magnetism. The establishment of ten magnetic observatories in the 

 Russian empire, on the recommendation of Humboldt, followed by a 

 cheerful and extensive co-operation throughout the civilized world ; the 

 vast mass of observations garnered up at these places, and the results 

 deduced from such ample materials by Gauss, Sabine, Lamont, and 

 many others, — all redound to the honor of Hansteen and Erman, as weU 

 as of Humboldt. The immediate effect of Hansteen's journey was the 

 establishment beyond a doubt of the existence of a magnetic pole in 

 Siberia, supplementary to that in British America, and of the biaxial 

 character of the earth's magnetism. 



Hansteen's elaborate treatise on Terrestrial Magnetism, to which 

 reference has already been made, discussed the isoclinic and iso- 

 dynamic lines, as well as those of declination ; and his Magnetic Atlas 

 contained maps of dip and intensity, excelled at the present day only 

 so far as the increased number of observations in the arctic and ant- 

 arctic regions, in the United States of America, and at the numei'ous 

 magnetic observatories, has supplied more accurate and abundant 

 data. The daily changes in the declination, the influence of the aurora 

 upon it, and the pi'obable dependence upon the sun of the fluctuations 

 in the earth's magnetism, were fully discussed by Hansteen. This 

 work, therefore, must ever remain a noble monument to his industry, 

 learning, and mathematical skill. 



After Hansteen's return from Siberia, the Norwegian government 

 furnished the means for building at Christiania a magnetic and meteor- 

 ological observatory, of which Hansteen was made director. Down to 

 the present moment valuable contributions to science have emanated 

 from it, increasing our knowledge of the earth's magnetism, of the 

 aurora, of shooting stars, and, in general, of astronomy and the physics 

 of the globe. The decennial period, as it is called, in the amplitude 

 of the daily oscillation of the declination-needle, first announced in 

 1831 by Lamont, from his observations made at the Munich magnetic 

 observatory, of which Sabine found the confirmation in the observations 



