3IR, JOULE ON THE MECHANICAL EQUIVALENT OF HEAT. 
71 
Table II. 
No. of experiment 
and cause of change 
of temperature. 
Total fall of 
weights in 
inches. 
Mean 
temperature 
of air. 
Difference he- 
tween mean of 
columns 5 and 6 
and column 3. 
Temperature of apparatus. 
Gain or loss of 
heat during 
experiment. 
Commencement 
of experiment. 
Termination of 
experiment. 
1 Friction 
! 265*42 
58*491 
i-452 + 
58*780 
61*107 
2*327 
gain 
1 Radiation ... 
0 
58*939 
2*056 + 
61*107 
60*884 
0*223 
loss 
2 Radiation ... 
0 
58*390 
0*237 — 
58*119 
58*188 
0*069 
gain 
2 Friction 
1265*77 
58*949 
0*467 + 
58*188 
60*644 
2*456 
gain 
3 Friction 
1265*73 
57-322 
1*203 + 
57*325 
59*725 
2*400 
gain 
3 Radiation ... 
0 
57-942 
1*678 + 
59-725 
59-515 
0*210 
loss 
4 Radiation ... 
0 
57-545 
0*010 — 
57-518 
57-553 
0*035 
gain 
4 Friction 
1264*72 
58-135 
0*624 + 
57-553 
59-965 
2*412 
gain 
5 Friction 
1265*73 
57-021 
0*907 + 
56-715 
59-141 
2*426 
gain 
5 Radiation ... 
0 
57-596 
1*474 + 
59-141 
58*999 
0*142 
loss 
6 Radiation ... 
0 
56-406 
0*174 + 
56-565 
56*595 
0*030 
gain 
6 Friction 
1265*65 
57-057 
0*749 + 
56*595 
59-017 
2*422 
gain 
♦ 
7 Friction 
1269-55 
58*319 
0*049 + 
57-115 
59*622 
2*507 
gain 
7 Radiation ... 
0 
58*771 
0*831 + 
59-622 
59-583 
0*039 
loss 
8 Radiation ... 
0 
60*363 
0*612 — 
59-691 
59-811 
0*120 
gain 
8 Friction 
1257-70 
60*842 
0*209 + 
59-811 
62-292 
2*481 
gain 
9 Friction 
1255*77 
60*282 
1*044 + 
60*129 
62*524 
2*395 
gain 
9 Radiation ... 
0 
60*862 
1*576 + 
62*524 
62*352 
0*172 
loss 
10 Friction 
1255*33 
60*725 
0*764 + 
60*266 
62*713 
2*447 
gain 
10 Radiation ... 
0 
61*340 
1*313 + 
62*713 
62*593 
0*120 
loss 
11 Radiation ... 
0 
58*654 
0*109 + 
58*755 
58*772 
0*017 
gain 
11 Friction 
1266*47 
59-234 
0*746 + 
58*772 
61*189 
2*417 
gain 
12 Radiation ... 
0 
56*436 
0*247 + 
56*673 
56*694 
0-021 
gain 
12 Friction 
1265*80 
57*240 
0*673 + 
56*694 
59-133 
2*439 
gain 
13 Friction 
1264*70 
55*002 
1*808 + 
55*638 
57-982 
2*344 
gain 
13 Radiation ... 
0 
55*633 
2*213 + 
57-982 
57-711 
0*271 
loss 
14 Friction 
1265*20 
54*219 
1*273 + 
54*290 
56-694 
2*404 
gain 
14 Radiation ... 
0 
54*595 
1-972 + 
56*694 
56*441 
0*253 
loss 
15 Radiation ... 
0 
53*476 
0*174 + 
53*633 
53*667 
0*034 
gain 
15 Friction 
1265*63 
53*995 
0*872 + 
53*667 
56*067 
2*400 
gain 
16 Radiation ... 
0 
52*082 
0*254 + 
52*332 
52*341 
0*009 
gain 
l6 Friction 
1265*45 
52*479 
1*047 + 
52*341 
54*711 
2*370 
gain 
17 Friction 
1257-50 
50*485 
1*453 + 
50*772 
53*105 
2*333 
gain 
17 Radiation ... 
0 
50*821 
2*164 + 
53*105 
52*865 
0*240 
loss 
18 Radiation ... 
0 
48*944 
0*450 — 
48*434 
48*554 
0*120 
gain 
18 Friction 
1257-50 
49*330 
0*462 + 
48*554 
51*031 
2*477 
gain 
19 Friction 
1257-50 
48*135 
1*273 + 
48*219 
50*598 
2*379 
gain 
19 Radiation ... 
0 
48*725 
1*780 + 
50*598 
50*413 
0*185 
loss 
20 Radiation ... 
0 
48*878 
0*148 — 
48*687 
48*773 
0*086 
gain 
20 Friction 
1257*50 
49*397 
0*597 + 
48*773 
51*216 
2*443 
gain 
Mean Friction 
1262*731 
0*8836 + 
2*41305 
p-ain 
Mean Radiation 
0 
0*8279 + 
0*06570 loss 
1 
2 
3 
4 
5 
6 
/ 
