334 
PEOFESSOE W. THOMSON AXD DE. J. P. JOULE OX THE 
aperture 2^ inches in diameter, and the ball was placed, at half an inch distance, in 
front of the aperture. We shall, as before, call that point of the ball which was nearest 
the wind, the Anterior Pole ; the most sheltered point, the Posterior Pole ; and the 
intermediate part, the Equator. The balls were furnished with thermo-electric junctions 
of thin copper and iron wires, made flat mth the suiTace, the junctions being in each 
case 90° apart from one another. 
Seeies XVIII. — |-inch Wooden BaU. 
Velocity of air. o 
68 ft. per sec. . . . Equator 0T14! colder than Anterior Pole . . . Posterior Pole 0'067 colder than Equator. 
Velocity of air. 
1-2 ... 
3-6 ... 
7-2 ... 
14-4 ... 
28-8 ... 
36 ... 
48 ... 
57-6 ... 
73 ... 
105 ... 
Seeies XIX. — I-inch Wooden Ball. 
o 
Equator 0’088 warmer than Anterior Pole. 
Equator 0'129 warmer than Amterior Pole ... Posterior Pole 0'03 warmer than Equator. 
Equator 0'160 warmer than Anterior Pole ... Posterior Pole 0'022 warmer than Equator. 
Equator 0’120 warmer than Anterior Pole ... Posterior Pole 0'018 colder than Equator. 
Equator 0 056 warmer than Anterior Pole .. , Posterior Pole O'OIS colder than Equator. 
Equator 0'008 colder than Anterior Pole. 
Equator 0'035 colder than Anterior Pole. 
Equator 0 056 colder than Anterior Pole Posterior Pole 0 090 colder than Equator. 
Equator 0'245 colder than Anterior Pole. 
Equator 0'380 colder than Anterior Pole Posterior Pole 0‘232 colder than Equator. 
In our next series, one junction was placed within the bellows, and the other in con- 
tact with the difierent parts of the I-inch ball. All the results will be seen to indicate, 
as might have been anticipated, that the junction within the bellows was warmer than 
any part of the ball. 
Seeies XX. 
Velocity of air. 
Pressure of air in the bellovrs, 
in inches of water. 
Cold of Anterior Pole, 
in respect to 
the inner juncdon. 
Cold of Equator, 
in respect to 
the inner jimction. 
Cold of Posterior Polco 
in respect to i 
the inner junction. ; 
1 
2-4 
0’003 estimated 
0-098 
O’OGo 
6-028 
3-6 
0'006 estimated 
0-094 
0-065 
0-028 
7-2 
0'025 estimated 
0-083 
0-103 
0-060 
14-4 
0-1 05 estimated 
0-110 
0-089 
0-109 ' 
28-8 
0-42 estimated 
0-102 
0-112 ’ 
73 
2‘7 estimated 
0-1S8 
0-309 
0-300 ' 
103 
5‘6 measured 
0-195 
0-360 
A further modiflcation of the experiments was made by placing a glass tube 3 feet 
long and of I^-inch interior diameter, within the aperture, so that two-thirds of the tube 
was inside, and one-third outside of the bellows. A ball furnished with junctions 90° 
distant from each other was placed within the tube. 
