440 



ON THE DECREMENT OF HEAT IN ASCENDING. 



Appendix I. 



Series V. — Jheels, Gangetic Delta, and Cliittagong. 



Locality. 



Date. 



a 



o 



eg 



> 



Depth. 



Temp, of 

 sunk Therm. 



e-i aj 



3° 



roximate 

 Temp, of 

 deduced. 



CD 43 

 (DEH 



ft* 















ftfl u 



X! 2 







H 









p, c3.5 



'/I 



si 







Feet. 



Ft. In. 











Silchar 



Nov. 27 to 30 



no 



2 7 



77-7 to 75-8 



55-0 to 81-7 



69-1 



+ 7-7 



Silhet . ... 



Dec. 3 „ 7 



133 





73-5 „ 73-7 



03-0 „ 74-5 



69-5 



+ 3-1 



Noacolly . 



„ 18 „ 19 



20 





73-3 



58-5 „ 70-5 



09-5 



+ 3-8 



Cliittagong . . . 



„ 23 „ 31 



191 





72-5 „ 73-0 



53-2 „ 75-0 



63-8 



+ 9-0 



j> 



Jan. 14 „ 10 







73-3 „ 73-7 



01-3 „ 78-7 



05-5 



+ 8-3 



„ flagstaff hill . 



Dec. 28 „ 30 



151 





72-0 „ 71-8 



55-2 „ 74-2 



65-3 



+ 0-0 



Hat-hazaree 



Jan. 4 „ 5 



20 





71-3 



50-5 „ 62-0 



05-0 



+ 0-3 



Sidhee . . . . 



„ 5 „ 6 



20 





71-0 



52-7 „ 70-2 



65-0 



+ 0-0 



Hattiah 



» 6 „ 9 



20 





*07'7 



50-2 „ 77-5 



64-5 



+ 3-2 



Seetakoond . . . 



,. 9 „ 14 



20 





73-3 „ 73-7 



55-2 „ 79-5 



70-2 



+ 3-3 



Calcutta** 



Jan. 10 Feb. 5 



18 





76-0 „ 77-0 



§50-5 „ 82-0 



09-3 



+ 7-2 



* Shaded by trees. ** Observations at the Mint, &c, by Mr. Muller. 



§ Observations for temperature of air, taken at the Observatory. 



ON THE DECREMENT OF TEMPERATURE IN ASCENDING THE SIKKIM 

 HIMALAYA MOUNTAINS AND KHASIA MOUNTAINS. 



I hate selected as many of my observations for temperature of the 

 air as appeared to be trustworthy, and which, also, were taken con- 

 temporaneously with others at Calcutta, and I have compared them 

 with the Calcutta observations, in order to find the ratio of decrement 

 of heat to an increase of elevation. The results of several sets of 

 observations are grouped together, but show so great an amount of 

 discrepancy, that it is evident that a long series of months and the 

 selection of several stations are necessary in a mountain country to 

 arrive at any accurate residts. Even at the stations where the most 

 numerous and the most trustworthy observations were recorded, the 

 results of different months differ extremely ; and with regard to the 

 other stations, where few observations were taken, each one is affected 

 differently from another at the same level with it, by the presence or 

 proximity of forest, by exposure to the east or west, to ascending or 



