266 



REPORT — 1864. 



Table III. — Showing the Temperature of the Air, as read off the curve 

 drawn through the observed temperatures, and as read off the ciu-ve of 

 most probable normal temperatiu'e, called adopted temperature, and the 

 calculated amount of disturbance from the assumed law of decrease of 

 temperature. 



FOTJETEENTH AsCENT. 



1863. 



Height, in feet, 

 above the mean 

 level of the sea. 



Temperature of the Air. 



Ascending. 



Between „■ „ 

 what CTcum 



times. 



August 31. 

 8000 



7000 



6000 

 5000 

 4000 



3000 

 2000 



ground. 



1000 

 ground. 



S 



o 



s 



stances 



Sun 

 shining 



Very 



dark 



cloud 



near us. 



Very 

 cold. 



Ob- 

 served 

 temp. 



Adopted 

 temp. 



In 

 clouds. 



340 



347 



39-0 

 42-8 



45-2 



47-5 

 51-3 

 S4'9 



64-0 



5o'o 

 51-0 

 64-0 



33'9 

 35-2 



38-1 



41-5 

 44-6 



47-6 

 50-7 

 539 



64-0 



Calcu- 

 L-ited 

 effect of 

 disturb- 

 ance. 



Descending. 



+ 



- o"5 



Between 

 what 

 times 



o 2 





Circum- 

 stances. 



■ l^ 



d 



Cirri 

 higher. 



In basin 

 ofclouds. 

 Just in 

 clouds. 



Ob- 

 served 

 temp. 



Stratum 



ofclouds 



above. 



In 



uniform 



mist. 



34"o 

 38-0 



38-3 

 389 



41-5 

 43-2 



46-3 

 49-0 



50"2 



51-0 

 53-5 



Adopted 

 temp. 



Calcu 

 lated 

 effect of 

 disturb- 

 ance. 



34-0 

 356 

 37-2 

 38-8 



4i'o 



43-5 



463 

 49"4 



50-2 

 515 

 539 



O'O 



+ 2-4 

 + II 

 -I- o-i 



+ o-S 



- 0-3 



O'O 



- 0-4 



O'O 



- 0-5 



- 0-4 



August 31. — The decrease of temperature within the &st 200 feet of the 

 earth in this ascent is very remarkable, no such rapid decrease having been 

 found in any other ascent : on the ground the temperature was 64°, and by 

 the time 200 feet was reached a decrease of 8° had taken place, the tempera- 

 tpe at 200 feet being 56° : from this height, up to 1200 feet, there was but 

 little change ; and above this the temperatm-e decreased from 2° to 3^° in each 

 succeeding 1000 feet, till 7000 feet were passed, when the balloon entered a 

 relatively warm current of au-. 



On descending, but Uttle change of temperature was experienced in passing 

 downwards from 7000 to 5500 feet ; then there was an increase of 2|° in 

 passing from 5000 feet to 4000 feet, and l°-7 from 4000 feet to 3000 feet; 

 the temperature then gradually increased to 40° at 1000 feet; at 860 feet it 

 was 49°-8, and on descending to nearly 800 feet it was 50|° ; on reaseending 

 to 1000 feet it increased to 51°, but decreased to 50° at 2000 feet. The 

 balloon then turned to descend, the temperature increasing to 51° on passing 

 downwards to 1000 feet, the same temperature as in the last ascension, and 

 to 53|° on the ground. 



