IN PASSING THROUGH THE ATMOSPHERE. 
249 
Table D. — Actinometer Observations at the Faulhorn, September 25, 1832. 
Hour. 
A 
Apparent 
time. 
Intervals 
observed. 
Actinometer B. 2. 
Mean. 
Remarks. 
r 
From 
To 
Mean. 
h m 
h m 
h m 
h m 
s 
7 26 
7 35| 
7 30f 
7 38f 
60 
16-4; 16-9; 17*6; 18*2; 
17-3 
7 46 
7 55i 
7 50f 
7 58f 
60 
21-6; 20-9; 21-7; 22-8; 
21-8 
8 7\ 
8 17 
8 121 
8 20L 
60 
25-7; 25*8; 25*4; 25 0; 
25-5 
8 28 
8 37£ 
8 32f 
8 40J 
60 
26-3; 26-4; 27-9; 27*8; 
27-1 
8 48| 
8 58 
8 53i 
9 1 i 
60 
27-1 ; 28-7 ; 29’2 ; 31-9; 
29-2 
9 15| 
9 24§ 
9 20 
9 28 
60 
30*6; 31-0; 31-8; 32*7; 
31-5 
9 37| 
9 46| 
9 42 
9 50 
60 
31-9; 32-1; 32-5; 33-1; 
32-4 
10 9 
10 18 
10 13! 
10 21 ! 
60 
36-9; 34-7; 36-0; 35-6; 
35-8 
10 29| 
10 38^ 
10 34 
10 42 
60 
38-0; 36-8; 36-4; 38*6; 
37-5 
10 47± 
10 56| 
10 52 
11 0 
60 
38-7; 37-3; 38-1 ; 38-0; 
38-0 
All in the open 
11 7" 
11 16 ! 
11 11 ! 
11 19§ 
60 
39-2; 40-3; 40-8; 41-3; 
40-4 
> air. 
11 26| 
11 35| 
11 31 
11 39 
60 
38-2; 38-9; 38'2 ; 37‘4 : 
38-2 
12 21 
12 30! 
12 25| 
12 33f 
60 
35-1 ; 36-3; 35-3; 35-6; 
35-6 
1 H 
1 14 
1 9! 
1 17! 
60 
32-3; 31-7; 35*1 ; 35-1 ; 
33-6 
1 27| 
1 37 
1 32i 
1 40A 
60 
32-2; 33'8 ; 34-2; 34-8; 
33-8 
2 27 
2 36| 
2 31f 
2 39f 
60 
31-5; 31*1 ; 31-0; 33*0; 
31-7 
2 47 j 
2 54| 
2 51 
2 59 
60 
29-7; 30-2; 28-9; 
29-6 
3 30 
3 39 
3 34! 
3 42! 
60 
25-0; 26*5; 24-9; 25-2; 
25-4 
4 16 | 
4 25! 
4 21 
4 29 
60 
21-3; 20-2; 20-1 ; 20-6 ; 
20-6 
4 43i 
4 52! 
4 48 
4 56 
60 
16*5; 16-2; 15-5 ; 15-8; 
16-0 
-J 
62. As the observations above and below are nearly contemporaneous, we might 
readily enough proceed to compare them directly. But I have thought it more exact, 
and also more instructive, to tabulate the meteorological and other data in the form 
of curves, and by graphical interpolation to obtain the desired quantities for the 
whole hours, by which means the errors of observation, and also local and momentary 
atmospheric changes are in some measure eliminated, and a kind of approximation 
made as to the mean condition, at any moment, of the mass of air under experiment, 
6800 feet in thickness, with respect to density, temperature, moisture, and opacity. 
The great advantages of this method will be seen in the sequel. The curves numbered I. 
to XIV. in Plates XVIII. to XXI. represent this interpolation, the points of observation 
being always connected by straight lines, and then a curve drawn easily through them. 
When reduced again to numbers, we have these regulated data contained in the fol- 
lowing Table, from which are deduced, — 1st, the intercepted mass of air; 2nd, the 
mean temperature of the mass of air ; 3rd, its mean relative dampness or ratio to 
saturation ; 4th, the loss of solar intensity in the passage of the rays from the level 
of the upper to the lower station ; 5th, the ratio of the intensity at the upper to that 
at the lower station. This Table also contains, — 6th, the sun’s apparent altitude for 
every hour of apparent time computed by the usual formula from the hour-angle, 
corrected for refraction and for the change of declination ; 7th, the approximate 
measure of the total mass of air traversed by the ray with the varying obliquity at 
each station ; 8th, the difference of the two last determinations which gives the effec- 
tive mass interposed between the stations. These masses of air are supposed to vary 
as the secant of the zenith distance (see Art. 33.). 
MDCCCXLII. 2 K 
