Second Series.— Thermo-Multiplier. 351 
employ a table of reduction, indicating the relation ‘subsisting 
between the dynamical effect or first are of impulsion, ‘and the 
statical effect or that of final deviation. My experiments have 
given the following results, and the last column indicates the ac- 
tual intensities taken from the preceding table, corresponding to 
‘the statical deviation in second column. 
Dynamical effect, or first Statical effect, or 
arc passed over. Permanent Deviation. Intensity. 
1.0 1.2 1.2 
2.0 25 2.35 
4.0 : 4.5 4.65 
6.0 6.7 71 
8.0 8.9 9.6 
10.0 11.1 12.05 
12.0 13.2 14.4 
14.0 15.3 16.9 
16.0 17.4 19.35 
18.0 19.45 21.75 
20.0 21.5 24.3 
9. The mode of observation by the first impulsive are I have 
invariably adopted for obtaining numerical results, and chiefly 
for these reasons: 1. It saves time, and thus renders consecutive 
observations comparable. 2. It prevents a long exposure of the 
pile to heat, which alters the zero point and injures its action. 
3. It almost annihilates the effect of conduction where substances, 
capable of retaining heat, are placed between the source of heat 
and the pile. 
10. It is a remarkable circumstance, that when both the cor- 
rections obtained from these tables are applied, we obtain (as 
far as 20° at least) a measure of intensity increasing, almost 
uniformly, with the are first run through. This is found to de- 
pend on the circumstance that the curve, expressive of forces, in 
terms of the stationary deviation, is convex towards the axis, or 
the forces increase more rapidly than the arcs ; whilst the curve, 
expressing the stationary in terms of the momentary deviations, 
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