THE MECHANICAL EQUIVALENT OF HEAT. 
443 
denoted by longer lines on the thermometer scale, the time of contact with the 
“ spider wire ” was not sufficiently definite, and the thickness of the graduation wmuld 
have made a considerable difference in the value of t. 
We did not attempt to record the time for every individual 1000 revolutions, but 
sufficient observations were taken to enable us to detect any change in rate. 
The pressure in the annular space round the calorimeter was high (‘98 millim.) 
during experiments 51 to 54, as we had only recently commenced re-exhausting. 
Table XIX.—Experiment LI. Aug. 1 1, 1892. 
McLeod gauge = 62 millims. Outside temp. = 241'3 A, = 300E„,. 
Pressure = ‘98 millim. Mass of water {in vacuo) = 103’01 grm. 
Clock error = *0004125. 
Experiment. 
Temperature Em. 
Time. 
Revolutions. 
Time. 
seconds. 
thousands. 
seconds. 
LI. 
86 
1110 
6 
0-8 
87 
137'9 
8 
67-6 
88 
164-8 
10 
134-0 
89 
193-0 
1 
167-4 
91 
248-4 
2 
200-7 
92 
275-9 
3 
234-3 
93 
302-5 
4 
267-7 
94 
330-2 
5 
300-9 
96 
386-0 
6 
334-0 
97 
412-5 
7 
36/-3 
98 
9 
433-5 
99 
469-3 
21 
501-0 
101 
524-4 
2 
533-9 
102 
552 8 
3 
567-2 
103 
579-8 
4 
601-0 
104 
609-8 
* • 
38 
1065-2 
121 
1095-6 
9 
1098-4 
122 
1124-2 
40 
1131-6 
123 
1154-4 
1 
1164-8 
124 
1183-3 
2 
1197-9 
126 
1244-3 
4 
1264-6 
127 
1274-0 
128 
1304-0 
7 
1364-7 
129 
1334-2 
8 
1397-8 
131 
1394-6 
50 
1463-9 
132 
1425-4 
1 
1497-3 
133 
1455-3 
2 
1530-5 
134 
1485-0 
53 
1563-5 
136 
1546-0 
. , 
76 
2332-4 
161 
2345-9 
7 
2365-8 
162 
2379-4 
8 
2399-3 
163 
2412-0 
9 
2432-6 
164 
2444-9 
80 
2466-0 
166 
2511-2 
1 
2499-3 
167 
2544-0 
3 
2565-8 
168 
2578-0 
4 
2599-4 
169 
2611-7 
5 
2632-5 
• - 
109 
3435-0 
3 L 2 
