AND DISPERSION IN ICELAND SPAR. 
443 
For g we have, as before, 
^=1-67557 Prism I. 
I’67545 Prism III. 
1 67556 Prism IV. 
Whence 
h\— 1 '67553 
and for when 
6»=89° 53' 4", Table XII. 
we have 
/x= P49430. 
Whence 
1-49430. 
Thus for g 
h\— 1 ‘67553 
1 ‘49430 
Tables XI. and XII. give the results of the calculations. 
Table XL—Results of Theory for F. 
0. 
From Theory. 
/ J 
From Experiment. 
Excess of 
Experiment. 
I. 
°0 2 40 
P66779 
1'66780 
+ 1 
II. 
4 19 58 
P66660 
1 -66663 
+ 3 
I. 
7 51 58 
1-66387 
1-66385 
- 2 
I. 
11 23 12 
1-65967 
1-65978 
+ 11 
I. 
17 8 26 
1-64987 
1-64996 
+ 9 
I. 
20 26 1 
1-64279 
1-64287 
+ 8 
II. 
23 50 45 
1-63451 
1-63455 
+ 4 
I. 
24 14 23 
1-63351 
1-63360 
+ 9 
I. 
25 49 35 
1-62934 
1-62930 
- 4 
II. 
29 18 42 
1-61965 
1-61974 
+ 9 
II. 
34 48 0 
1-60336 
1-60336 
0 
II. 
38 58 47 
1-59048 
1-59058 
+ 10 
II. 
40 49 21 
1-58478 
1-58487 
+ 9 
III. 
45 45 57 
1-57000 
P57014 
+ 14 
II. 
46 46 2 
1’56645 
1-56653 
+ 8 
III. 
49 23 10 
1 "55861 
P55876 
+ 15 
III. 
52 42 6 
1-54902 
1-54914 
+ 12 
III. 
58 39 10 
1-53303 
1-53312 
+ 9 
III. 
61 39 33 
1-52570 
1-52573 
+ 3 
III. 
63 9 6 
1-52228 
1-52241 
+ 13 
III. 
66 14 27 
1-51579 
1-51571 
- 8 
III. 
72 18 55 
1-50476 
1-50475 
- 1 
III. 
75 36 18 
1-50009 
1-50005 
- 4 
III. 
79 6 26 
1-49612 
1-49610 
- 2 
IV. 
80 14 4 
1-49507 
1-49507 
0 
IV. 
87 6 40 
1-49112 
1-49114 
+ 2 
IV. 
89 49 6 
1-49074 
1-49074 
0 
