ASSOCIATION UNIT OF RESISTANCE IN ABSOLUTE MEASURE. 
695 
Table VI.—Deflections with wire circuit open. 
Number of teeth. 
60 
45 
35 
30 
Mean of first series .... 
3-89 
5-22 
6-74 
7-85 
,, second series . . . 
3-93 
5-24 
6-77 
7-82 
,, third series .... 
3-93 
5-24 
6-76 
7-92 
After the wire had been re- 
moved, December 7 ... 
• • 
5-23 
6-76 
• • 
Numbers proportional to speed 
3-94 
5-25 
6-76 
7-88 
On the whole, it would appear to he the most probable explanation that there were 
currents in the ring flowing in circuits not conjugate to the wire circuit, and therefore 
influencing the induction phenomena. But whatever view we may take on this 
matter, there is no reason to doubt that the true value will be obtained by intro¬ 
ducing such a correction proportional to the square of the speed as will harmonise the 
several results, a course equivalent to determining the coefficient of self-induction from 
the spinnings themselves. In this way the numbers corresponding to any two speeds 
may be made arbitrarily to agree, but the numbers for the two remaining speeds will 
afford a test of the admissibility of this procedure. The only hypothesis upon which 
the simple mean of the numbers already obtained for the various speeds should be 
taken as final would appear to be one that would attribute to the discrepancies an 
accidental character, and seems quite out of the question. 
The simplest way to carry out the correction will be to determine the amount of 
the coefficient from the two extreme speeds. The squares of the speeds are as 
1 • A6. . 14 4 . A . 
1 . 9 . 49 . , 
so that the difference of the numbers for the two extreme speeds, 23‘638 —23'619, 
i.e., ‘019, is three times the quantity by which the lowest is to be reduced. We are 
accordingly to subtract respectively 
*0063, AfX‘0063, br^X-0063, 4 X‘0063 
with the following results. 
Table VII.—Third series. 
Number of teeth. 
Mean. 
60. 
45. 
35. 
30. 
Resistance of standard at 13°, uncorrected 
23-619 
23-621 
23-630 
23-638 
23-627 
Correction proportional to square of speed 
•006 
•Oil 
•018 
■025 
. . 
Resistance of standard at 13°, corrected . 
23-613 
23-610 
23-612 
23-613 
23-612 
4 u 
MDCCCLXXXII. 
