58 
MR. F. E. SMITH ON THE ABSOLUTE MEASUREMENTS OF A 
Table III.—Giving the Mean Diameters of the Coils at 20°'0 C. 
Coil on cylinder 
Nol 
F ebruary-March, 
1912. 
April, 
(a) 
1913. 
(P) 
Mean. 
cm. 
cm. 
cm. 
cm. 
1 
35 ‘88083 
35-8807., 
35-8806g 
35-88074 
2 
35‘8817 6 
35-8815., 
35•8815 0 
35"8815a 
3 
35‘8855 4 
35-8853 0 
35•8853 4 
35-8853 9 
4 
35‘8867 4 
35-8866, 
35-8864 4 
35-8866 0 
The values recorded in columns 2 and 3 are exactly the means of 192 and 102 
measurements respectively. The values in column 4 are not quite the means of the 
48 observations. The cylinders are not quite circular in cross-section, and the mean 
of 48 measurements in three planes should, in general, be different from the mean of 
Table IV.—Giving the Results of Measurements of the Diameters of the Coils on 
Cylinder No. 1. Temperature 20°'0 C. 
Axial plane No. . 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
Measurements on 
turn No. 
Diameter = 35 • 8750 cm. + 
Mean. 
A 
A 
/*• 
/X. 
A 
/*• 
A 
fi. 
A 
ix. 
fX. 
F- 
1 
29 
14 
22 
27 
30 
30 
25-s 
12 
27 
26 
31 
36 
36 
23 
29- 8 
24 
34 
30 
32 
36 
35 
35 
33-7 
36 
35 
37 
42 
41 
47 
45 
41-2 
48 
41 
39 
39 
46 
48 
49 
43- 7 
60 
40 
42 
48 
47 
49 
48 
45-7 
72 
61 
57 
59 
61 
64 
63 
60-g 
84 
65 
66 
69 
70 
75 
65 
68-3 
96 
67 
65 
76 
74 
72 
70 
70- r 
108 
70 
69 
72 
69 
78 
66 
70-7 
120 
58 
61 
63 
65 
72 
66 
64"2 
132 
66 
65 
73 
74 
73 
68 
69-s 
144 
67 
63 
68 
69 
71 
72 
68-3 
156 
66 
70 
74 
76 
70 
73 
71-5 
168 
75 
67 
73 
71 
72 
71 
71-5 
180 
65 
67 
70 
72 
65 
66 
67- 5 
192 
64 
65 
70 
74 
78 
70 
70- 2 
Mean . . = 
55 -! 
53 - 9 
51- 2 
55-2 
55-s 
59-9 
58-4 
60-e 
60-s 
61-e 
58-4 
56-s 
57 - 2 
. ■ 
.•. Mean diameter (centre to centre of wires) = 35• 87 50 + 0" 00572 = 35-88 072 cm. at 20°-0 C. 
