INTENSITY OF THE CHEMICAL ACTION OF TOTAL DAYLIGHT. 
671 
June 18th, 1873. (Protector for first four hours.) 
Clock. 
Hand. 
Time. 
n . 
Mean 
reading. 
I. 
I 
n 
Time. 
Mean 
reading. 
I. 
I 
n 
h m 
h m 
4 30 a.m. 
31-7 
168 
0-28 
0-017 
5 30 „ | 
20-2 
151 
0-49 
0-024 
31-7 
118 
0-76 
0-024 
1-94 x mean 
= 0-046 
6 30 „ | 
10-2 
146 
0-54 
0-053 
17-1 
117 
0-76 
0-044 
1-94 x mean 
=0-093 
7 30 „ | 
6-9 
17-1 
152 
61 
0- 48 
1- 20 
0-070 
0-070 
No observa 
tions. 
1-94 x mean 
= 0-136 
8 30 „ | 
3-6 
147 
0-53 
0-147 
5-3 
122 
0-73 
0-138 
1-94 x mean 
= 0-123 
9 30 „ | 
3-6 
111 
0-80 
0-222 
5-3 
57 
1-24 
0-234 
Mean 
0-228 
f 
2-3 
133 
0-65 
0-282 
f 
3 
116 
0-77 
0-257 
10 30 „ { 
2-8 
118 
0-76 
0-271 
10 30 A.M. \ 
5 
22 
1-57 
0-314 
1 
6-9 
10 
1-68 
0-243 
l 
5 
42 
1-39 
0-278 
Mean 
0-265 
Mean 
0-283 
Diff. 
— 0-018 
f 
3-6 
139 
0-61 
0-169 
f 
5 
144 
0-56 
0-112 
11 30 „ 1 
6-9 
107 
0-82 
0-111 
11 30 „ i 
5 
143 
0-57 
0-114 
1 
9-6 
83 
0-95 
0-099 
1 
10 
68 
1-10 
0-110 
Mean 
0-129 
Mean 
0-112 
Diff. 
+0-017 
r 
3-6 
119 
0-75 
0-208 
r 
5 
71 
1-06 
0-212 
12 30 p.m. 1 
5-3 
62 
1-19 
0-225 
12 30p.m. ■< 
5 
71 
1-06 
0-212 
1 
6-9 
30 
1-49 
0-216 
1 
7 
25 
1-54 
0-220 
Mean 
0-216 
Mean 
0-215 
Diff. 
+ 0-001 
1 30 „ | 
10-2 
17-1 
133 
73 
0- 65 
1- 03 
0-064 
0-060 
1 30 „ 
No obse 
rvntions 
Mean 
0-062 
10 
166 
0-31 
0-031 
2 30 „ 
17T 
147 
0-53 
0-031 
2 30 „ | 
15 
157 
0-42 
0-028 
Mean 
0-030 
Diff. 
+ 0-001 
4 x 
MDCCCLXXIV. 
