THE MECHANICAL EQUIVALENT OF HEAT. 
411 
Table XII. 
Date. 
C°. 
R (at 17°). 
R corrected 
for “plugs.” 
R corrected 
for bridge. 
True ohms. 
Aug. 6 . . . 
18-701 
8-70152 
8-70514 
8-70923 
8-68809 
„ 6 . . . 
13-133 
8-53685 
8-54041 
8-54442 
8-52368 
„ 10 . . . 
25-217 
8-89343 
8-89701 
8-90119 
8-87958 
„ 17 . . . 
19-231 
8-71690 
8-72046 
8-72456 
8-70338 
„ 24 . . . 
20-.337 
8-74906 
8-75260 
8-7.5671 
8-/3545 
„ 31 . . . 
17-066 
8-65267 
8-65627 
8-66034 
8-639.32 
Sept. 4 . . . 
15-325 
8-60104 
8-60459 
8-60863 
8-58773 
Between September 4 and 11 the coil was readjusted, and was probably somewhat 
strained in the process. The value of R was slightly increased. 
Table XIII. 
Date. 
C°. 
R (at 17°). 
R corrected 
for “ plugs.” 
R corrected 
for bridge. 
True ohms’. 
Sept. 11 . . . 
19-560 
8-73058 
8-73416 ^ 
8-73827 
8-71706 
„ 11 . . . 
25-522 
8-90563 
8-90923 
8-91342 
8-89178 
„ 11 . . . 
13-280 
8-.54471 
8-54826 
8-55228 
8-.53I52 
„ 11 . . . 
15-086 
8-59816 
8-60171 
8-60575 
8-58486 
» 11 . . . 
22-154 
8-80618 
8-80975 
8-81389 
8-792.50 
, „ 11 . . . 
23-274 
8-83966 
8-84326 
8-84742 
8-82594 
„ 14 . . . 
16-952 
8-65268 
8-65628 
8-660.35 
8-63933 
„ 19 . . . 
18-697 
8-70415 
8-70777 
8-71186 
8-69072 
The sixth figure is, of course, unnecessary. The numbers in the first and last 
columns were plotted on a very large scale, so that the fifth figure could be read 
distinctly. The resulting curves differ in no respect from those given by platinum 
thermometers. The difference between the curve reading (at any of the above 
temperatures) and the corresponding value in the table in no case exceeds '0005 [i.e., 
1 in 17,000). 
The values of II after September 4 exceed the values before that date (when the 
temperature is the same) by ‘0038. 
The values of R (true ohms) at other temperatures than those in the above tables 
were obtained from the curves.* 
* In order to trace the changes in the specific heat of water throughout our range, we had decided to 
find the time of rising 1° at each of the following temperatures, viz., 14°, 15°, 16°, 18°, 20°, 22°, 24°, and 
25° C. It would have been difficult, if not impossible, to arrange our actual observations throughout our 
experiments so that they were exactly grouped about these points. The value of each millim. of our 
thermometer stem varied as the temperature changed, and the above temperatures in no case corresponded 
with any integral number. The values of our variables at these temperatures had to be obtained by 
3 G 2 
