ON COLOUR PHOTOMETRY. 
555 
Table VIII.— V. H.’s Curves. 
I. 
II. 
III. 
IY. 
V. 
YI. 
YII. 
Scale 
number. 
Wave¬ 
length. 
Mean 
reading of 
extinction in 
millionths of 
original 
luminosity. 
Adopted 
reading in 
millionths of 
original 
luminosity. 
Persistency 
curve 
530 
Luminosity 
curve. 
Absolute 
luminosity 
of extinction 
IY. x YI. 
ad. reading' 
75 ' 
57 
6423 
500 
500 
11 
31 
206 
56 
6330 
350 
350 
1-5 
43 
200 
54 
6152 
200 
180 
2-9 
61 
146-4 
52 
5996 
100 
100 
5-3 
70 
93-3 
50 
5850 
40 
40 
133 
73 
38-9 
48 
5720 
. # 
25 
21-2 
69 
23 
46 
5596 
10 
10 
53-0 
63 
8-4 
45 
5538 
6-5 
6-5 
81-6 
58 
5-0 
44 
5481 
6-0 
57 
93 
54 
4-1 
42 
5373 
5-5 
5-3 
100 
46 
3-3 
40 
5270 
5-5 
5-4 
98-2 
36 
2-6 
38 
5172 
57 
5-7 
93 
24 
1-8 
36 
5085 
6'7 
6-5 
81-6 
15 
1-3 
34 
5002 
7-0 
7-0 
75-7 
9-5 
•89 
32 
4924 
8-5 
8-5 
62-3 
7-0 
•79 
30 
4848 
107 
10-5 
50-5 
5-0 
•70 
28 
4776 
16 
16 
331 
3-7 
•79 
26 
4707 
, , 
22-5 
23-5 
27 
•81 
24 
4639 
30 
31 
171 
1-82 
•75 
22 
4578 
42-5 
42 
12-6 
1-4 
•78 
20 
4517 
55 
55 
9-6 
1-0 
•73 
16 
4404 
105 
100 
5-3 
•7 
•93 
12 
4296 
175 
170 
31 
•45 
1-02 
10 
4245 
200 
200 
2-7 
•34 
•91 
4 b 2 
