60 
SIR WILLIAM THOMSON ON THE 
Table I. — Temperature of Cold Water. 
Results for + M. 
Operations. 
14 on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
,, on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
,, on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
Deflections. 
+ 26 
-26 
+ 33 
-33 
+ 36 
-36 
+ 36-5 
-365 
+ 33-5 
-33-5 
+ 19 
-19 
+ 12 
-12 
+ 6 
- 6 
+ 2 
— 2 
0 
0 
- 4 
+ 4 
- 7-5 
+ 7-5 
- 9 
+ 9 
-11 
+ 11 
-11-5 
+ 11--5 
-12 
+ 12 
-13 
+ 13 
I 
} 
Current 
strengths. 
0 
10 
22 
44 
67 
143 
180 
220 
246 
267 
310 
352 
403 
447 
503 
600 
830 
Results for — M. 
Operations. 
14 on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
., off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
„ off 
„ on 
» off 
„ on 
off 
Deflections. 
0 
0 
-27 
+ 27 
-36 1 
+ 36 / 
-36-51 
+ 36-5 / 
—33-51 
+ 33-5 / 
-25 1 
+ 25 / 
- 19 1 
+ 19 / 
-15 
+ 15 
-11 
+ 11 
- 4 
+ 4 
0 
0 
5 
5 
7 
7 
9 
- 9 
+ 13 
-13 
+ 
+ 
+ 
Current 
strengths. 
11 
22 
46 
66 
96 
145 
169 
195 
223 
267 
290 
355 
394 
430 
830 
207. We see from tire above table that the vertical component of tlie magnetizing 
force of the earth is balanced by an opposite magnetizing force due to a current measured 
by 11 divisions of the battery galvanometer, or about - 2 - 5 - of the Yillari critical value 
of the magnetizing force, with 14 lbs. “off” and “on.” 
If now a Daniell’s cell be taken as one volt, or 10 8 on the C. G. S. system of units, 
we have for the magnetizing force of 1 cell estimated in the manner explained above 
1 CQ.Q y 1 08 
(Part VI., § 183), the value in ^ ‘'■gog x -^ 9 = 6*443. But the strength of the mag¬ 
netizing current of 1 cell was measured bv a deflection on the scale of the battery gal¬ 
vanometer of about 130 divisions, or a little more than twelve tunes the amount of the 
magnetizing force of the earth. Hence we have in absolute measure, ‘5 as a rough 
