796 
DR. T. R„ ROBINSON ON THE DETERMINATION OF 
containing any power of V but the square. If we reduce the mean a of No. I. and 
No. III. in the ratio of the areas jf- and the air’s density, we get 2*477, so nearly 
that actually found that we may fairly assume the a to be proportional to the areas 
of the cups. 
Table VIII. 
No. III. y=201'3; June 19, Bar. 29*83 ; Therm. 67. 
No. 
D. 
S. 
N. 
b. 
V. 
W. 
f". 
C. 
T. 
e. 
a. 
I. 
18 
180 
52-5 
120-4 
11-34 
1-08 
17-4 
67-25 
1326-6 
62°1 
10-496 
II. 
21 
33 
58 6 
118-4 
12-675 
1-10 
22-0 
92 
1918-2 
61-2 
1 2 625 
III. 
24 
68 
101 
14-69 
1-29 
29-9 
107-5 
2293-9 
63 0 
I! 466 
IV. 
27 
74 4 
822 
16-07 
1 58 
36-2 
142 
3118-1 
64-2 
13-385 
V. 
30 
81-3 
93-2 
17-56 
1-40 
43 8 
158 
347.7-5 
61-2 
12-063 
VI. 
33 
84 5 
68-3 
18-255 
1-89 
47 6 
167 
3650-2 
612 
12-393 
VII. 
30 
916 
63-4 
19-70 
2-05 
56 2 
188 
4178-2 
45-2 
12-571 
VIM. 
39 
99 
58-6 
21-39 
2-22 
67-4 
201 
4509-4 
89-4 
11-521 
IX. 
42 
103-7 
59 6 
2240 
2 18 
74-7 
221 
5074 5 
75‘6 
11-714 
X. 
45 
107-5 
64-2 
23-06 
2 03 
79 7 
248 
5482-3 
82-8 
11-843 
XI. 
48 
31 
115 
51-4 
24-84 
2-53 
94-4 
341 
6828 0 
57-6 
13-098 
The mean of the eleven = 12*10 7 ; that of No. I. reduced to the same air density 
= 12*383. Making reasonable allowance for errors, I think we may infer that the a is 
not changed by reducing the arms of the anemometer to half their length. 
(28.) I tried similar measures with No. IV., but had very indifferent success. The 
main cause of this was the bad quality of a supply of oil which had just been sent in 
for lubricating the machinery, and which probably prevented the excursion of the 
anemometer beyond the point of balanced tension. From the high temperature, also, 
it was necessary to have all the windows open. Eleven were taken, of which from 
the second to the seventh, C changed only from 23 to 25*5, though V varied from 
18*1 to 28*5. C then passed at once to 94, and continued increasing. The extreme 
F + T . . 
hypothesis would make a= — - ; it is precarious, but I give those that are not 
palpably wrong for what they are worth. 
Table IX. 
No. IV. f— 185*0; June 21, Bar. 29*66 ; Therm. 75*0. 
No. 
D. 
S. 
N. 
l. 
V. 
C. 
T. 
6. 
a. 
I. 
15 
180 
66 
361 
14-26 
0 36 
20-2 
20 
364-8 
72°0 
2-940 
II. 
17 
84 
153 
18-15 
0-85 
33-6 
23 
426-9 
82-8 
2-147 
VIII. 
33 
141 
1 17-4 
30-46 
1-11 
105-3 
94 
1967 7 
68-4 
2-614 
IX. 
34 
13 
150 
70 8 
32-41 
1 84 
121-5 
96 
2017-5 
75'6 
2 480 
X. 
39 
159 
91 6 
34-35 
1-42 
129-4 
121 
2594-8 
89-4 
2 677 
XI. 
42 
31 
139 
723 
34"3o 
1*80 
129-4 
97 
2042-8 
79-2 
2 168 
