oct. — dec. 1857.] Scientific Intelligence. 



139 



valley of Yarkand, a region never visited before, not even by Marco 

 Polo. It is a vast depression of between 3,000 and 4,000 feet, 

 separating the Kuenlun, on the northern frontier of India, from 

 the Syan-Chane, or mountains of Central Asia, on the southern 

 border of Russia. They then returned to Ladak, and entered into 

 the Punjaub by different routes through Cashmere. ^ After a two 

 years' negotiation, M. Herrmann was, at the commencement of 

 1857, admitted into Nepaul, where he determined the altitudes 

 of the Machipoora and Mount Yassa, which have hitherto been 

 vaguely called the Dhawalaghiri, which means nothing else but 

 " snowy crests," and is applicable to all snow-capped mountains. 

 M. Robert proceeded to Bombay through Scinde, Kutch, and Gu- 

 zerat, where he surveyed the chain called the Salt Range, and de- 

 termined the changes effected in the course of centuries in the 

 course of several rivers. Before returning to Europe, he stayed 

 three months in Ceylon. M. Adolphus visited various parts of the 

 Punjaub and Cabul, previous to returning to the Himalaya, where 

 he still is. The chief results obtained from this careful explora- 

 tion of Asia are the following: — The Himalaya mountains every- 

 where exercise a decided influence over all the elements of the 

 magnetic force ; the declination everywhere presents a slight de- 

 viation, causing the needle to converge towards the central parts of 

 that enormous mass, and the magnetic intensity is greater than it 

 would be anywhere else under an equal latitude. In the south of 

 India, the increase of the magnetic intensity from south to north is 

 extremely rapid. The lines of equal magnetic intensity have a re- 

 markable form, similar and perhaps parallel to those of certain 

 groups of isothermal lines. The three travellers have collected all 

 the materials necessary to ascertain this important fact. Irregular 

 local variations in terrestrial magnetism are rare in those regions. 

 In the Deccan and Behar the rocks are magnetic. On the Hima- 

 laya, at altitudes of 17,000 and even 20,000 feet, the daily maximum 

 and minimum variations of the barometer occurred nearly about the 

 same hours as in the plains below. Again, at the above altitudes, 

 the inversion of the curves of daily variation, which is met with on 

 the Alps, does not take place. At the altitude of 17,000 feet, the di- 

 minution of transparency produced by a stratum of air of the thick- 

 ness of 3,000 feet is no longer distinguishable by the eye. During the 



