118 Report on the Progress of the Magnetic Survey. [No. 2. 



The erosion is very deep in the valleys on the northern margin 

 of the Kuenluen. In the inner parts of the Kuenluen, the valleys 

 present for the most part a Thibetan character, displaying a broad 

 basis slightly inclined, over which the water spreads itself in many 

 channels, and afterwards evaporates completely. 



Extensive glaciers are chiefly met with in the range to the north 

 of Karakorum, (*. e. in the ridge above mentioned in a direction 

 from west to east,) and another group, apparently the largest accu- 

 mulation of glaciers in the Kuenluen, was found in the environs of 

 Sassar, but both much smaller than the groups near the Diamer, 

 to the north-west, investigated by our brother Adolphe. 



Two fine groups of hot springs of analogous character, (both 

 depositing great quantities of lime, and smelling slightly of hydro- 

 sulphuric gas) were found inNubra. The temperature of the hottest 

 springs of the group near Panamick was 78° C. == 172.6° Fahr. • of 

 the other group near Changlung, 74.1° C. = 165.4° Fahr. A spring 

 of ordinary water at the same height as Changlung had a tem- 

 perature of 10.1° C. == 50.2° Fahr. There is another group of hot 

 springs mentioned above, situated a little below the lake Kiuk-kiul, 

 (14,800 feet). Their deposits are nearly pure muriate of soda. 

 These springs, more than fifty in number, are partly situated in 

 the very bed of the river Karakash, and surrounded closely by 

 its cold waters. The temperature of these springs is from 25° to 

 49° C. =77° to 120° Fahrenheit. 



In these neighbourhoods, and also lower down in the Karakash 

 Valley, are found several groups of salt pools, conical depressions 

 of the ground filled with solid salt and a concentrated solution of 

 salt. The salt was nearly pure table salt ; but some pools were 

 not yet so far advanced in the progress of concentration that solid 

 salt had deposited itself. 



The high temperature of these salt pools was very remarkable. 

 The salt deposit forms a stratum over the excavation containing 

 the salt-water and a nearly complete cover on its surface. The 

 great diathermaneity of salt (a stratum of salt allows 92 out of 100 

 thermic rays to pass through it, while an equal thickness of glass 

 only allows 39,) is the principal cause of the excess of temperature 

 In consequence of this physical property of the salt, the tempera- 



