AND TRANSMITTED BY CERTAIN KINDS OF GLASS. 
255 
Flint Glass. 49 mm. thick, a? = 19 mm. 
A. 
Eeaclings. 
Half 
differences. 
a — X. 
b. 
Percentage of 
light transmitted. 
Percentage of 
light transmitted. 
Mean of A and B. 
cm. 
cm. 
94-5-I09-2 
7-3 
192-8 
209-3 
84-85 
94-5-I09-0 
7'2 
192-9 
209-2 
85 02 
94-9-I09-0 
7-0 
I93-I 
209-0 
85^36 
95-3-I09-2 
6-9 
193-2 
208-9 
85-53 
85-19 
B. 
93-I-I06-8 
6-8 
193-3 
208-8 
85-70 
93-3-I07-4 
7-0 
193-1 
209-0 
85-36 
93-I-107-0 
6-9 
193-2 
208-9 
85-53 
: 93-9-I07-3 
6-7 
193-4 
208-7 
85-88 
85-62 
85-40 
Flint Glass. 69'5 mm. thick, a: = 27 mm. 
A. 
Beading?. 
Half 
differences. 
Ct — X. 
b. 
Percentage of 
light transmitted. 
Percentage of 
light transmitted. 
Mean of A and B. 
cm. 
cm. 
93-1-110-3 
8’6 
190-7 
210-6 
81-99 
93-5-1] 0-3 
8-4 
190-9 
210-4 
82-32 
93-6-110-4 
8-4 
190-9 
210-4 
82-32 
82-21 
B. 
92-5-108-9 
8-2 
191-1 
210-2 
82-65 
92-9-108-9 
8-0 
191-3 
210-0 
82-98 
1 93-1-109 0 
7-9 
1914 
209-9 
83-15 
1 
i 
82-93 
82-57 
