“ NEW FORCE ” OF M. J. TIIORE. 
457 
No. of 
experiment. 
Material of pillar. 
Maximum 
speed of one 
revolution. 
No. of 
revolutions. 
Exciting agent. 
29 
Ivory, lampblacked. 
seconds. 
18 
4-0 
Face 
30 
7 
10-25 
Hot water 
31 
Ebonite, lampblacked.. 
14 
4-75 
Face 
32 
7 
11-75 
Hot water 
33 
Boxwood wedge, lampblacked, edge to 
19 
3-5 
Face 
34 
cylinder 
Boxwood wedge, lampblacked, flat side 
28 
2-75 
tt 
35 
to cylinder 
Boxwood wedge, lampblacked, flat side 
4 
16-75 
Hot water 
36 
to cylinder 
Brass tube, lampblacked. 
10 
7-25 
Face 
37 
tt tt . 
10 
10-5 
Hot water 
38 
tt tt . 
28 
2-5 
Candle 8 inches from 
39 
Square brass bar, lampblacked, edge 
16 
6-5 
cylinder 
Face 
40 
to cylinder 
Square brass bar, lampblacked, edge 
8 
8-0 
Hot water 
41 
to cylinder 
Square brass bar’, lampblacked, flat 
18 
3-75 
Face 
42 
side to cylinder 
Square brass bar, lampblacked, flat 
8 
8-25 
Hot water 
43 
side to cylinder 
Brass wedge, edge to cylinder, lamp- 
8 
11-5 
tt 
44 
Glass rod, 65 mm. long, 1"5 mm. thick, 
17 
3 
Face 
45 
lampblacked 
Glass rod, 65 mm. long, 1*5 mm. thick, 
16 
4-5 
Hot water 
lampblacked 
These results leave little doubt that the action exerted by the face was due to the 
radiant heat emitted by it. M. Thore, however, considers that heat is without action. 
This being a most important point, and one which must be settled beyond all doubt, I 
devised the following experiments :—A large sheet of thick cardboard had an oval 
aperture 5 inches by 3 "5 inches cut in the centre. This was fixed in front of the 
suspended cylinder, about 8 inches off. A Winchester quart-bottle covered with 
slightly damped brown paper was arranged on a stand close behind the aperture, and 
easily removable. By this arrangement I could compare the effect of a given surface 
of the face with that of the same surface of radiation from moist brown paper heated 
to the temperature of the face, which for this purpose was taken as 33° C. The 
cylinder in each case was of blackened ivory. Hie following Table gives the mean of 
a number of experiments :— 
No. of 
experiment. 
Material of pillar. 
Maximum 
speed of one 
revolution. 
No. of 
revolutions. 
Exciting agent. 
46 
Blackened brass tube. 
seconds. 
17 
4-0 
Face 
47 
tt tt . 
15 
3-5 
Bottle 
3 N 
MDCCCLXXXVII.—A. 
