1064 DR. T. R. ROBINSON ON THE DETERMINATION OF 
Reducing the first 21 of Table X. by formula XIII., and with my present values of 
a and y I get a?= 1*3744, 2=0*889, and the limit = 2*317. 
The W’s used in computing these constants were certainly inaccurate. I measured 
them in the plane of the centre of the anemometer, but as the disturbance of the air 
will be as Yd-^Xsin 0, AY must be less in the upper semicircle than in the lower, 
while it acts with less mechanical advantage in lessening v. It must also be kept in 
mind that any measure of W is an average one, and that it may have very different 
values in parts of the air vortex. 
(72.) In E 3 , the cross remaining the same the 9" cups were set at 12" from the axis; 
it is my No. III. In it the constant for v' is half that for K’s v, and the normal 
friction is double = 60*8. With the approximate a?= 1*7481 and 2=2*056, the results 
are given in the following Table, in which the densities are omitted as involved in <f)'. 
Table XXII. 
No. 
Dir. 
Time. 
A. 
A'. 
Log. <p\ 
V. 
v'. 
V. 
V'. 
V - \'. 
I. 
N.E. 
s. 
474 
108 
165 
0-67241 
0-976 
1-491 
3-151 
5’590 
-2-439 
II. 
N.E. 
605"6 
313 
540-5 
0-62808 
4-434 
3-828 
12-637 
12-539 
+ 0-098 
III. 
S.E. 
541-7 
281-5 
505 5 
0'64167 
4-453 
3-998 
12-693 
13-093 
-0-400 
IV. 
S.E. b. S. 
550-9 
570 
10110 
0-63633 
8-864 
7-861 
25-135 
25‘206 
-0-071 
V. 
S.W. b. S. 
503-6 
203-0 
342 0 
0-63394 
3-453 
2-909 
9-795 
9-853 
-0-058 
VI. 
S.E. 
446-2 
261-6 
453 
0-63185 
5 0235 
4-350 
14-298 
14-179 
+ 0-119 
VII. 
S. 
601-3 
611 
1134 
0-68300 
8-705 
8-078 
24686 
25-891 
. -1-205 
VIII. 
S. 
547-1 
440-3 
752 
0-68300 
6-895 
5-888 
19-562 
18-971 
+ 0-591 
IX. 
S.W. 
607-8 
453 - 5 
782 
0'63397 
6-348 
5-551 
18-020 
17-779 
+ 0-241 
X. 
w. 
552-1 
380 
647 
0-63127 
5-896 
5-019 
16-754 
16-083 
+ 0-671 
XI. 
S.W. 
599-4 
133 
240 
0-63644 
1-914 
1-727 
5*617 
6-254 
-0-637 
XII. 
S.W. 
475-8 
340 
576-5 
0-63295 
6-121 
5-190 
17-389 
16-797 
+ 0-592 
XIII. 
S.W. 
480-8 
330 
582 
0-63966 
5-345 
5-185 
15-201 
16-624 
-1-423 
XIV. 
W. b. N. 
572-1 
192 
331-5 
0-63283 
3-212 
2-773 
9-212 
8-938 
+ 0-274 
XV. 
N.W. 
663'5 
314 
535 5 
0-62821 
4-045 
3-4495 
11-584 
11-381 
+ 0-203 
XVI. 
N.W. 
515*2 
290 
497 
0-62623 
4-3765 
3-674 
12-474 
12-068 
+ 0-406 
XVII. 
N.W. 
600 
248 2 
4125 
0-62710 
3-544 
2-945 
10-139 
9-845 
+ 0-294 
XVIII. 
N.W. 
660 
178 
313-8 
0-62130 
2-311 
2-037 
6-704 
7-127 
-0-423 
XIX. 
S.W. 
946 6 
488-7 
752 
0-63008 
4-4205 
3-401 
12-598 
11-243 
+ 1-355 
XX. 
S. 
720 
354 
599 
0-63364 
4-212 
3-564 
12-014 
11-453 
+ 0-561 
S(A" — V') =—1*251 which divided by Se'=145*185, we have dx— —0*0086 
a;=l*7395, 2 = 2 * 026 , and the limit =3*163. These are larger than those of E x . 
The results obtained in paragraphs (38) and (39) would make it less, but in the 
present work it is the rule that diminishing the length of the arms increases x. 
(73.) In Eg the 9" inch cups were fixed W' distance from the axis : too near for 
good work, but I wished to see the effect on x. With its approximate values 
x— 2*1359 and 2=3*562, I computed Table XXIII. 
