ON EIGHT BALLOON ASCENTS IN 1862. 479 
The numbers in every one of these columns are affected with a change of 
sign, and, therefore, no certain difference is shown over the determination of 
the dew-point as found by any method or instrument over that found by 
any other. 
By taking the means of all in each group of 5000 feet, giving weight 
according to the number of experiments upon which each result is based, we 
have :— 
From the ground to 5000 feet high the temperature of the dew-point as 
determined by— 
Dry and Wet bulb (free) 
Experiments, 
Was 0°-4 higher than as found by Dry and Wet (aspirated) ..from 4 
», thé samé as found by Daniell’s Hygrometer .......... wine 
», 22 higher than as found by Regnault’s Hygrometer .. ,, 3 
Dry and Wet bulb (aspirated) 
Was 0°-1 higher than as found by Daniell’s Hygrometer .... ,, 2 
Tape es . 3 59 Regnault’s 9 sH¥S 5S ae 
Daniell’s Hygrometer 
Was 1°-0 higher than as found by Regnault’s Hygrometer .. ,, 3 
From 5000 feet to 10,000 feet the temperature of the dew-point as de- 
termined by 
Dry and Wet (free) 
Was 0°2 higher than as found by Dry and Wet (aspirated) ..from 1 
oa Neal a * is Daniell’s Hygrometer .... ,, 29. 
a. 1°83 a a ps Regnault’s 3 , ee Ae ee 
Dry and Wet (aspirated) 
Was 5°-9 higher than as found by Daniell’s Hygrometer .... 5, 2 
“4, 0%7-lower 3 35 Regnault’s 5 (FET ee Ue 
From 10,000 to 15,000 feet the temperature of the dew-point as deter- 
mined by i 
Dry and Wet (free) 
Was 2°-1 lower than as found by Dry and Wet Saag from 3 
-5, 2°-0 higher 53 4». _ Daniell’s Hygrometer . . “oe 
», 07 lower pa is Regnault’s po T atAee% hat i eu 
Dry and Wet (aspirated) 
Was 6°-2 higher than as found by Daniell’s Hygrometer .... ,, 
,, 14 lower 4 Regnault’s - RAGE 
“ 
“ 
Or 
Daniell’s Hygrometer 
Was 2°2 lower than as found by Regnault’s Hygrometer.... ,, 4 
