MR. G. A. SCHOTT OX THE REFLECTION AND REFRACTION OF LIGHT. 865 
Fire-opal—Air (29, p. 279). 
/X = 1-623 ; A =r - -0040, B = -00594, F = + -000063, E = + -0625 ; 
e = not given. 
0- 
/3. 
w 
observed. 
'3' 
calculated. 
Differ¬ 
ence. 
Differ¬ 
ence, 
Cauchy. 
X 
"“2 
observed. 
0 cal- 
cnlated. 
Differ¬ 
ence. 
t 
Differ¬ 
ence, 
Cauchy. 
o 
60 
1 
0 
o 
27 
30 
o 
3 
/ 
8 
o 
3 
i 
4 
+ 
/ 
4 
•843 
•810 
+ •033 
59 
45 
24 
30 
2 
44 
2 
44 
0 
.810 
•785 
“h *025 
59 
.30 
21 
30 
2 
22 
2 
27 
— 
5 
•734 
•753 
-•019 
59 
15 
19 
30 
2 
8 
2 
11 
— 
3 
•703 
•714 
-•on 
59 
0 
18 
0 
1 
57 
1 
57 
0 
*"6 
•666 
•664 
+ •002 
• 
58 
45 
16 
30 
1 
47 
1 
47 
0 
o 
■+^ 
•609 
•605 
+ •004 
0? 
58 
30 
10 
0 
1 
44 
1 
41 
+ 
3 
c5 
•.540 
•537 
+ •003 
58 
22 
15 
0 
1 
37 
1 
39 
— 
2 
o 
•500 
•499 
+ •001 
58 
15 
15 
15 
1 
38 
1 
39 
— 
1 
ce 
o 
•455 
•465 
-•010 
O 
58 
0 
16 
45 
1 
49 
1 
43 
+ 
6 
o 
-.397 
•397 
•000 
r* 
57 
45 
17 
0 
1 
50 
1 
53 
— 
3 
1^; 
•337 
-.337 
•000 
>5 
57 
30 
19 
0 
2 
4 
2 
5 
— 
1 
•295 
•287 
+ •008 
57 
0 
22 
45 
2 
31 
2 
34 
— 
3 
•220 
•215 
+ -005 
56 
30 
30 
0 
3 
28 
3 
16 
+ 1 
2 
•163 
•169 
-•006 
56 
0 
32 
30 
3 
50 
3 
56 
— 
6 
•143 
•138 
+ -005 
Probable error . 
• • 
±3' 
•10 
±•0280 
Hyalite—Air (29, p. 281). 
/X = 1-421 ; A = -000, B = -00040, F = + -00026, E = — -0150 ; e = — -0074. 
h- 
/L 
observed. 
calcu 
oT 
lated. 
Differ¬ 
ence. 
Differ¬ 
ence, 
Cauchy. 
, X 
^ 2 
observed. 
e cal¬ 
culated. 
Differ¬ 
ence. 
Differ¬ 
ence, 
Cauchy. 
0 
56 
0 
0 
18 
/ 
0 
o 
1 
57 
O 
1 
/ 
51 
+ 6 
-•924 
-•934 
+ •010 
55 
30 
11 
30 
1 
13 
1 
6 
+ 7 
-•898 
-•885 
-•013 
<D 
55 
15 
5 
37 
0 
36 
0 
45 
- 9 
-•8.50 
-•822 
-•028 
55 
0 
4 
22 
0 
28 
0 
28 
0 
-•641 
-•656 
+ •015 
54 
52 
4 
6 
0 
26 
0 
25 
+ 1 
-•500 
-•489 
-•on 
54 
45 
4 
15 
0 
27 
0 
27 
0 
-•329 
-•345 
+ •016 
o 
54 
30 
8 
0 
0 
51 
0 
43 
+ 8 
O 
-177 
-•178 
+ •001 
o 
54 
15 
10 
56 
1 
10 
1 
4 
+ 6 
l2i 
-•140 
-•114 
-•028 
53 
30 
18 
30 
2 
1 
2 
12 
-11 
-•092 
-•055 
-•037 
Probable error . 
±4'-65 
• • 
• • 
±•0218 
5 s 
MDCCCXCIV.—A. 
