660 
ME. H. E. EOSCOE ON A METHOD OE MEASURING THE 
Millims. 
I. 
Millims. 
I. 1 
Millims. 
I. 
Millims. 
I. 
173 
0-28 
151 
0-70 1 
130 
1-02 
70 
1-76 
170 
0-27 
150 
0-72 
123 
1-09 
59 
1-72 
168 
0-29 
147: 
0-77 
119 
1:12 
21 
2-44 
. 166 
0-31 
146 
0-79 
106 
1-24 
15 
2-69 
163 
0-46 
132 
1-00 
101 
1-35 
158 
0-52 
131 
1-01 
82 
1:51 
Hence the following Calibration Table is obtained for the same strip by graphical 
interpolation : — 
I. 
n. 
I. 
II. 
I. 
II. 
L 1 
IL | 
I. 
II. 
10 
2-89 
45 
2-03 
80 
1-54 
! 
115 
1,15 
150 
0-67 
1 
2-85 
6 
2-02 
1 
1-53 
6 1 
1-15 
1 
0-65 
2 
2-81 
7 
2-00 
2 
1-51 
7 
1-14 
2 
0-63 
3 
2-77 
8 
1-99 
3 
1-51 
8 
1-13 
3 
0-61 
4 
2-73 
9 
1-97 
4 
1-50 
9 ! 
1-12 
4 
0-59 
5 
2-69 
50 
1-96 
5 
1-49 
120 
1-12 
5 
0-58 
6 
2-64 
1 
1-94 
6 
1-48 
1 
1-11 
6 
0-56 
7 
2-60 
2 
1-93 
7 
T48 
2 
1-10 
7 
0-54 
8 
2-56 
3 
1-91 
8 
1-47 
3 
1-09 
8 
0-52 
9 
2-52 
4 
1-90 
9 
1-47 
4 
1-07 
9 
0-51 
20 
2-48 
5 
1-88 
90 
1-46 
5 
1-06 
160 
0-50 
1 
2-44 
6 
1-86 
1 
1-45 
6 
1-05 
1 
0-49 
2 
2-42 
7 
1-84 
2 
1-44 
7 
1-04 
2 
0-48 
3 
2-41 
8 
1-82 
3 
1-43 
8 
1-03 
3 
0-46 
4 
2-39 
9 
1-81 
4 
1-42 
9 
1-02 
4 
0-41 
5 
2-37 
60 
1-80 
5 
1-41 
130 
1-01 
5 
0-36 
6 
2-35 
1 
1-79 
6 
1-40 
1 
1-00 
6 
0-31 
7 
2-34 
2 
1-78 
7 
1-39 
2 
0-99 
7 
0-30 
8 
2-32 
3 
1-77 
8 
1-38 
3 
0-97 
8 
0-29 
9 
2-31 
4 
1-76 
9 
1-37 
4 
0-95 
9 
0-28 
30 
2-29 
5 
1-75 
100 
1-36 
5 
0-94 
170 
0-27 
1 
2-28 
6 
1-74 
1 
1-35 
6 
0-92 
1 
0-26 
2 
2-26 
7 
1-73 
2 
1-32 
7 
0-90 
2 
0-25 
3 
2-24 
8 
1-72 
3 
1-30 
8 
0-88 
3 
0'24 
4 
2-23 
9 
1-71 
4 
1-28 
9 
0-86 
4 
0-22 
5 
2-21 
70 
1-69 
5 
1-26 
140 
0-85 
5 
0-20 
6 
2-19 
1 
1-68 
6 
1-24 
1 
0-83 
6 
0:18 
7 
2-18 
2 
1-66 
7 
1-23 
2 
0-81 
7 
0:16 
8 
2-16 
3 
1-65 
8 
1-22 
3 
0-79 
8 
OKI 5: 
9 
2-15 
4 
1-63 
9 
1-21 
4 
0-77 
9 
0-13 
40 
2-13 
5 
1-62 
110 
1-20 
5 
0-76 
180 
0-10 
1 
2-11 
6 
1-60 
1 
1-19 
6 
0-74 
2 
2-09 
7 
1-59 
2 
1-18 
: T 
0-72 
3 
2-07 
8 
1-57 
3 
1-17 
8 
0-70 
4 
2-05 
9 
1-56 
4 
1-16 
9 
0-68 
As a check upon this method of calibrating the fixed strip, a series of tints, obtained 
by exposure in quick succession in the hand-insolator * for known but varying times to 
the diffused light of a cloudless sky, were read off on the same strip. A Calibration 
Table was then constructed for the strip, and the values therein contained were found 
to coincide (within the limits of observational error) with those obtained by the former 
method. 
* Philosophical Transactions, 1865, vol. civ. p. 612. 
