Sept. 1849. HOT SITJNGS. 133 



taken on these excursions are sufficiently illustrated by 

 those of Donkia pass : they served chiefly to perfect my 

 map, measure the surrounding peaks, and determine the 

 elevation reached by plants ; all of which were slow 

 operations, the weather of this month being so bad 

 that I rarely returned dry to my tent ; fog and drizzle, 

 if not sleet and snow, coming on during every day, 

 without exception. 



T made frequent excursions to the great glacier of 

 Kinchinjhow. Its valley is about four miles long, broad 

 and flat : Chango-khang * rears its blue and white cliffs 

 4,500 feet above its Avest flank, and throws down 

 avalanches of stones and snow into the valley. Hot 

 springs f burst from the ground near some granite rocks 

 on its floor, about 10,000 feet above the sea, and only a 

 mile below the glacier, and the water collects in pools : its 

 temperature is 110°, and in places 116°, or 4° hotter than 

 that of the Yeumtong hot-springs, though 4000 feet higher, 

 and of precisely the same character. A Barbarea and 

 some other plants make the neighbourhood of the hot- 

 springs a little oasis, and the large marmot is common, 

 uttering its sharp, chirping squeak. 



The terminal moraine is about 500 feet high, quite 



* The elevation of this mountain is about 20,560 feet, by the mean of several 

 observations taken from surrounding localities. 



+ Supposing the mean temperature of the air at the elevation of the Momay 

 springs to be 20° or 28°, which may be approximately assumed, and that, as some 

 suppose, the heat of thermal springs is due to the internal temperature of the globe ; 

 then according to the law of increment of heat in descending (of 1° for fifty feet) 

 we should find the temperature of 110° at a depth of 4,100 feet, or at 11,900 

 feet above the level of the sea. Direct experiment with internal heat has not, 

 however, been carried beyond 2000 feet below the surface, and as the ratio of 

 increment diminishes with the depth, that above assigned to the temperature 

 of 110° is no doubt much too little. The Momay springs more probably owe 

 their temperature to chemical decomposition of sulphurets of metal.-?. I found 

 pyrites in Tibet on the north flank of the mountain Kinchinjhow, in limestones 

 ;i associated with shales. 



