166 
MR. GLAISHER ON THE RADIATION OF HEAT, 
Excess of the reading of a self-registering minimum thermometer placed in air at 
the height of four feet, protected from the effects of radiation, above that of a 
similar thermometer placed in the focus of a metallic parabolic reflector fully ex- 
posed to the sky on every night, arranged according to the state of the sky with 
respect to the quantity of clouds. 
Number 
of the 
Tables. 
1841. 
Month. 
General state of the sky during the ni 
ght previous to reading the instruments. 
Cloudy. 
Broken clouds. 
Half-cloudv. 
Principally clear. 
Cloudless. 
Day and 
hour of 
reading. 
Excess of 
the reading 
of the ther- 
mometer in 
air above 
that placed 
in the focus 
of the re- 
flector. 
Day and 
hour of 
reading. 
Excess of 
the reading 
of the ther- 
mometer in 
air above 
that placed 
in the focus 
of the re- 
flector. 
Day and 
hour of 
reading. 
Excess of 
the reading 
of the ther- 
mometer in 
air above 
that placed 
in the focus 
of the re- 
flector. 
Day and 
hour of 
reading. 
Excess of 
the reading 
of the ther- 
mometer in 
air above 
that placed 
in the focus 
of the re- 
flector. 
Day and 
hour of 
reading. 
Excess of 
the reading 
of the ther- 
mometer in 
air above 
that placed 
in the focus 
of the re- 
flector. 
d h 
O 
d h 
d h 
d h 
O 
d h 
O 
Feb. 
4 21 
4-8 
24 21 
3-8 
17 21 
19 21 
5-8 
5 21 
3-0 
28 21 
4-1 
18 21 
3-2 
6 21 
0*8 
7 21 
2-8 
8 21 
2-3 
9 21 
2-8 
10 21 
5-7 
11 21 
1-9 
12 21 
1-7 
1— 1 
13 21 
0-8 
14 21 
- 0-6 
15 21 
1-2 
16 21 
2-9 
20 21 
2-3 
21 21 
2-1 
22 21 
1-1 
23 21 
1-5 
25 21 
2-4 
27 21 
1*3 
March 
13 21 
- 0*5 
1 21 
1-8 
7 21 
5-8 
2 21 
5-2 
6 21 
9-4 
4 21 
2-1 
9 21 
5-3 
3 21 
4-9 
8 21 
7-2 
30 21 
2-0 
20 21 
3-5 
14 21 
4-2 
5 21 
5-1 
10 21 
4-7 
31 21 
0-2 
23 21 
40 
22 21 
4-3 
17 21 
9-7 
11 21 
7-0 
28 21 
4-4 
26 21 
5-9 
18 21 
5-4 
12 21 
5-3 
* 
15 21 
8-8 
ij 
16 21 
13-4 
19 21 
6-7 
24 21 
7-3 
25 21 
6-9 
27 21 
5-7 
29 21 
2-7 
April 
10 21 
2-1 
1 21 
3*5 
5 21 
4-5 
14 21 
7*2 
2 21 
8-6 
13 21 
2-8 
6 21 
2-7 
9 21 
4-7 
21 21 
3*5 
3 21 
7-8 
. 
22 21 
0-7 
7 21 
1-9 
12 21 
6-6 
23 21 
6*5 
4 21 
11*5 
24 21 
2-1 
11 21 
1-3 
19 21 
7*9 
26 21 
5-6 
8 21 
11-8 
hj 
18 21 
(- 2 - 4 ) 
20 21 
4*7 
28 21 
5-6 
15 21 
7-6 
25 21 
6-3 
27 21 
5-4 
29 21 
6-2 
16 21 
10-2 
30 21 
8-1 
