ON FIVE BALLOON ASCENTS IN 1863. 493 
of humidity varied very much, from 100 at 13,000 and 14,000 feet to 19 at 
20,000 feet and to 40 at 23,000 feet. 
On descending, the temperature of the dew-point separated from that of the 
air, and was 30° less at 21,000 feet ; on passing then into fog, the moisture 
increased so rapidly that at 19,800 feet there was only 6° difference between 
these temperatures ; it again separated, and again approached whilst passing 
through rain and snow; on passing below the snow at 10,000 feet, the air at 
first became drier, but afterwards the increase of the temperature of the dew- 
point was more rapid than that of the air, and the air became more humid. 
Both the temperature of the air and the distribution of the water in this 
ascent were very remarkable. 
Tasre VIL. (continued.)—Twetrra Ascent. 
Humidity of the Air. 
Ascending. | Descending. 
Height, in feet, 
ieee Se Tempe- ._ | Degree Tempe- . | Degree 
Oa et Circum-|rature of| pee. of eevee Cireum-jrature of Rlesc) xf , 
times. ri sate vapour. to times. | Stances- eee vapour, ia 
July 11. Es 6..\| ie a in. 
4600 BG sl 503] 1365) 595 jeer |” pal Ge's) “Seed 75 
4400 anzia| 49°8| -358| 72 | 8 |. 5 | 49°5| 7355] 65 
4200 He Bl] 480] :335)- 65 |e ka | Be | 492) “some 63 
4000 a~ 478 *333) 62 a | ge | 47°) “328m 56 
3800 44°6| °295| 62 E me 49°2|) °351| 59 
3600 g 43°3 | 280/) £156 ene Ja | 50°0| °361] 59 
3400 es 43°5| 1283 |° 6s Wpme Z| sr0| °374|. 62 
3200 ae 43°5| °283] 54 S me} Sao)! “374ie 99 
3000 =, 43°4| ‘281| 53 aS 50°9| °373| 60 
2800 2 43°2)| 279) 52 wo Sun 50°7| °370| 60 
2600 Ne 43°5| °283) 52 * seen 50°5| °367| 60 
2400 =| Agi2 S270)|| 56  |faintly.| 50°2| °364| 69 
2200 a x 43°0| °277| 49 B The balloon thien 
2000 ie a 43°0| °277| 48 turned |to ascend. 
1800 =k 2 AGio}| GguT $2 
1600 he a 50.0} °361| 60 
1400 7 & 50°2| °364| 59 
1200 = 48°5| 342] 54 
1000 479) °323) 44 
800 47°5| °329| 47 
600 48:6) 343] 46 
400 50:0} °361| 46 
200 SEE 375:) Ha 
2 S22, 305 | hat 
July 11.—The balloon first rose to 4600 feet, the degree of humidity 
increasing with elevation ; it then descended to 2600 feet, and the tempe- 
rature of the dew-point was nearly constant. The balloon then turned to 
ascend, and reached a height of 6600 feet; the humidity increased as before 
to 5400 feet, and then became somewhat less humid; on descending, the air 
at first increased in humidity, and then decreased, being driest at the lowest 
part of the descent, viz. 1000 feet. The balloon then turned to ascend for a 
third time and reached 2600 feet, with a somewhat drier atmosphere than had 
been met with at this elevation on this day; at this time the track of the balloon 
was near the sea; on descending to 800 feet the air was more humid ; and this 
was found to be the case by ascending for the fourth time to 1600 feet, and 
again confirmed on finally descending to the height of 800 feet, when the 
instruments were packed up. 
