the Rarefaction and Condensation of Air. 

 Table IV. 



379 



Nature of experiment. 





3004 



30-10 



3010 



Expansion . 

 Interpolation 

 Expansion . 

 Interpolation 

 Expansion , 



Interpolation ..,! 



Expansion 30*10 



Interpolation ... 



Expansion 30*23 



Interpolation ...I 



Expansion 30*20 



Interpolation 



Mean of expts. "I 

 of expansion J 



Mean of inter- \ 

 polations .../ 



Corrected result 



3013 



30-13 





2862 



O 4J 



c5 



2807 

 2*723 



2807 

 3039 

 2919 



2859 



2859 



2726 



S 2 

 5 2 



C3^ 



2670 



2587 



2670 



2903 



2782 



2723 



J723 



55-7 



55-4 



54-6 



54-25 



53-6 



534 



4905 



491 



506 



51-1 



490 



48-85 



Difference, 



Temp, of water. 



Before 

 expt. 



0-405+ 56-207 

 0-579 + 56-004 

 0-022+ '54-714 

 0-276+ :54-536 

 0-760+54-460 

 0-839 + ^54-259 

 0-307+ 49-456 



After 

 expt. 



0158+ 

 0-508— 

 1-063- 

 0-355- 



0-277— 



0-105 + 

 0-085+ 



49-258 

 50-176 

 50-017 

 48-728 

 48-573 



56004 

 55-954 

 54 530 

 54-516 

 54-259 

 54-219 

 49-258 

 49-258 

 50-008 

 50-057 

 48-563 

 48*573 



Gain or loss of 

 heat. 



0-203 loss. 

 050 loss. 

 '0-184 loss. 

 ,0 020 loss. 

 .0-201 loss. 

 0-040 loss. 

 10-1 98 loss. 

 



0-168 loss. 

 0-040 gain. 

 0165 loss. 

 



0-1865 loss. 

 0-01 17 loss. 



0-1 738 loss. 



The cold produced was diffused through 21 '17 lbs. of water, 

 14 lbs. of copper, 8 lbs. of lead, and 7 lbs. of tinned iron. 

 Hence we find that a quantity of cold was produced in the 

 experiments sufficient to cause the temperature of a lb. of 

 water to decrease by ^"•OSS. At the same time a mechanical 

 force was developed, which could raise a column of the atmo- 

 sphere, of an inch square at the base, to the altitude of 2723 

 inches ; or in other words, could raise 3352 lbs. to the height 

 of one foot. For each degree of heat lost, there was therefore 

 generated a force sufficient to raise 820 lbs. to the height of 

 one foot. 



In the two following series the experiments were varied by 

 compressing and measuring out different volumes of air. 



On reducing the results of these experiments in the man- 

 ner before indicated, we find that in the experiments of 

 Table V. 814. lbs., and in tho.se of Table VI. 760 lbs. were 

 raised to the height of a foot, for every degree of heat per lb. 

 of water lost. 



These results are inexplicable if heat be a substance. If 

 that were the case, the same quantity of heat would, have 

 been absorbed by the rarefaction which took place in the ex- 

 periments of Table IV., as was evolved by the corresponding 



