256 
SIR J. CONROY ON THE AMOUNT OF LIGHT REFLECTED 
Flint Glass. 
91'3 mm. thick, x = S5 mm. 
1 
A. 
Eeadings. 
Half 
differences. 
a — X. 
b. 
Percentage of 
light transmitted. 
Percentage of 1 
light transmitted. 
Mean of A and B.j 
1 
cm. 
cm. 
1 
927-110-6 
8-9 
189-6 
210-9 
80-82 
1 
92-9-110-9 
9-0 
189-5 
211-0 
80-66 
i 
93-1-110-7 
8-8 
189-7 
210-8 
80-98 
80-82 
B. 
1 
91-6-110-1 
9-2 
189-3 
211-2 
80-34 
92-0-110-2 
9-1 
189-4 
211-1 
80-50 
92-3-109-8 
8-7 
189-8 
210-7 
81-15 
i 
80-66 
80-74 
Three plates of 6 mm. Crown Glass. Cemented together, x = 6 mm. 
A. 
1 
Eeadings. 
1 
Half 
differences. 
a — x» 
h. 
1 
Percentage of j 
light transmitted. 
cm. 
cm. 
' 
96-2-108-6 
6-2 
195-2 
208-2 
87-90 1 
96-3-108-4 
6-0 
195-4 
208-0 
88-25 
96-3-108-6 
6-1 
195-3 
208-1 
88-08 
i 
88-08 
