118 SKETCH OF THE LIFE AND ACHIEVEMENTS 



netic needle ; and his numerous investigations 

 during his travels, at this time, and subse- 

 quently, on one and the same magnetic needle, 

 not only animated other able naturalists to in- 

 stitute similar observations, but furnished the 

 material afterwards used by Biot in the calcu- 

 lation of the magnetic equator. 



Humboldt had, together with Gay-Lussac, 

 with whom he entered into a most intimate 

 elation, continued these observations, and dis- 

 covered that neither the great mountain-chains, 

 nor yet the active volcanoes, exercise a per- 

 ceptible influence on the magnetic force, but 

 that it gradually changes with the distance 

 from the equator. 



It is supposed that Baron Humboldt prepared 

 one of his few w^orks in the German language 

 in Berlin, because in the following year (1808) 

 appeared his " Ansichten der Natur," dedicated 

 to his brother Wilhelm. The powerful impres- 

 sion produced on Wilhelm von Humboldt by 

 a perusal of this work is strikingly reflected in 

 a poem, in recognition of this dedication, which 

 Alexander concealed from the eyes of the world 

 until the death of Wilhelm. In this poem Wil- 

 helm placed himself amid the same wild and 

 sublime nature, in the midst of the undeveloped 

 higher existence, and realized also the conscious- 



