450 DECREMENT OF TEMPERATURE IN ASCENDING. Appendix I. 



The total number of comparative observations taken during that 

 journey, amounted to 563, and the mean equivalent was 1° = 303 

 feet, but I rejected many of the observations that were obviously 

 unworthy of confidence. 



V. — Miscellaneous observations {chiefly during the rainy season) taken 

 during my journey into Sikkim and the frontier of Tibet, between 

 May 2nd and December 25th, 1848. The observations were 

 reduced as in the previous instance. The rains on this occasion 

 were unusually 'protracted, and cannot be said to have ceased till 

 mid-winter, which partly accounts for the very high temperatures. 



Elevations. 



No. 

 of Stations. 



No. 

 of Observations. 



Equivalent. 



1,000 to 4,000 ft. 

 4,000 to 8,000 

 8,000 to 12,000 

 12,000 to 18,000 



10 

 21 



18 

 29 



45 



283 

 343 

 219 



l°=422ft. 

 1°=336 

 1°=355 

 1° = 417 





Sum 78 



Sum 890 



1° = 383 ft. 



The great elevation of the temperature in the lowest elevations is 

 accounted for by the heating of the valleys wherein these observa- 

 tions were taken, and especially of the rocks on their floors. The 

 increase with the elevation, of the three succeeding sets, arises from 

 the fact that the loftier regions are far within the mountain region, 

 and are less forest clad and more sunny than the outer Himalaya. 



A considerable number of observations were taken during this 

 journey at night, when none are recorded at Calcutta, but which are 

 comparable with contemporaneous observations taken by Mr. Muller 

 at Dorjiling. These being all taken during the three most rainy 

 months, when the temperature varies but very little during the whole 

 twenty-four hours, I expected satisfactory results, but they proved 

 very irregular and anomalous. 



The means were— 



At 21 stations of greater elevation than Dorjiling 

 At 17 , t lower in elevation 



1° = 348 feet. 

 1°=447 „ 



VI. — Sixty-four contemporaneous observations at Jillapahar, 7,430 feet, 

 and the bed of the Great Rungeet river, 818 feet ; taken in 

 January and February , give 1°=322/^. 



