ON EIGHT BALLOON ASCENTS IN 1862, 467 
Tazre VII. (continued.) 
Hygrometrical results. 
. Ascending, Descending. 
eight, in feet, |~ 
ne Betw x Tempe- . | Degree Tempe- . , | Degree 
= een! Circum -|rature o Lage of Beaween Circum. |T2ture of plastic - of 
N ‘ -| force o: i- = i- 
times, | Stances go vapour, ‘ath Piss stances, rong vapour, ee 
August 21. ef | ne Sie 
14.000 . |—14'0] ‘o22] 318 =7270} ‘OIR| I 
13000 =| re Im EoW | 786) 628 2 = —13'0| ‘023]. 17 
12000 3 B. |+ 3°70] ‘ogo| 36 B q. oo} 7044] 28 
11000 if es) 1o'°0| 068] 43 wn 5. l#13°r| °078]. 43 
10000 ee? 2 14°1| *082| 46 os S 1g'0| *103| 51 
gooo ra) 3S 20°38} -r12] 56 “3 a 18:0] *o98| 42 
8000 2 < Dez ©1361) Ox ~ 19'°0| *103} 38 
7000 g 32°0| ‘x81| 71 B In 2'0| ‘18r]. 58 
6000 a In 39°0| *238| 97 g |Cloud.| 37-5) +225] 89 
5000 a, cloud.| 41°6| °263] 93 4 B 380} *229] 81 
4000 of - | 4o'8} ‘ass! 78 o 4o5| ‘252! 78 
3000 4 = 46°8 *321| 86 9, = AB'7 | 307 less 
2000 f | Os | 5°°9| °373} 88 » S 47°0| °323] 77 
1000 £ | Ss | 568) 462) 96 5 & | 49°7| °357| 74 
° ee Goro} 518) 94 |f A | 2. | 56°] *449)] 82 
August 21.—The temperature of the dew-point decreased from 60° on the 
ground to 57° at 400 feet, then increased to 59° from 500 to 700 feet whilst 
passing through a thick mist, and to 60° at 1000 feet; a decline then took 
place to 50°8 at 1300 feet, and 50°9 at 2000 feet; from 2000 feet to 3200 
feet there was at first a gradual, then more rapid decline to 40°8 at 4000 feet ; 
on entering cloud the dew-point increased to 41°-6, and on leaving it at about 
6000 feet there was a sudden fall of 2°. The relative humidity was 94 on the 
ground ; the air was saturated for 200 feet from 500 to 700 feet; the humi- 
dity was 74 at 1000 feet, 79 at 1300 feet, and 97 in the cloud. Above the 
cloud the dew-point decreased quickly and with but slight irregularities till 
the height of 10,400 feet, where it was 144°, with a humidity of 48; at 
14,000 feet the dew-point was —14°, and the air was dry, the relative 
humidity being 18. Above 14,000 feet the temperature of the dew-point 
declined to —20°, with a humidity of 12 only. During the half-hour this 
height was maintained the temperature of the air increased, whilst that of 
the dew-point diminished, so that the air became drier. On descending the 
air continued dry, the dew-point increased from —22° at 14,000 feet to 
+19° at 10,000 feet, the humidity increasing to 51; there was but little 
variation in the dew-point in the next 2000 feet, but during this space the 
temperature of the air increased 7°, so that the relative humidity was irre- 
gular. At 7500 feet the dew-point was 20°, at 6900 feet it was 42°; on 
approaching the clouds at the former height the relative humidity was 38, 
and at the latter it was 88. Whilst passing through the cloud both the 
temperatures of the air and dew-point declined, the latter to 383°, and the 
humidity was 89. On descending below the cloud the dew-point increased 
gradually from 382° at 4000 feet high, then quickly to 45°7 at’ 3000 feet, 
then fell to 44°-7 at 2500 feet, then increased to 56° on reaching the ground. 
At 5800 feet the relative humidity was 83, between 2500 feet and 1500 feet 
it was 76 or 77, and it was 71 on the earth. 
In this series, till the clouds were passed, there were two or three layers 
of moist air; but from the time of passing above the clouds, the air was 
constantly increasing in dryness till the greatest height was attained, and 
‘ poss 212 ; 
