228 



Messrs. Rosa and Smith on a Calorimetric 



Table I. 



Test of the Calorimeter. 



(ft) 



(<0 





Period in 





seconds 



Time. 



for each 

 lOOOgrm. 



h. m. s. 



of water. 





1 53 00 





2 19 45 



1605 



2 46 50 



1625 



3 13 55 



1625 



3 41 15 



1640 



4 09 10 



1675 



4 37 10 



1680 



5 04 10 



1620 



5 32 15 



1685 



6 01 00 



1725 



i 



(d) 



Average 

 tempera- 

 ture of 



the 

 ingoing 

 water. 



(«) (/) 



Average ' Increase 

 tempera- in tempe- 



15-66 

 15-70 

 1574 

 15-70 

 15-72 

 15 57 

 1564 

 1555 

 15-57 



I ture of 



| the out- 



i i going 



water. 



rat lire of 

 I each 

 lOOOgrm. 

 I of water. 

 \{e)-{d). 



(A) 



iff) 



Total 



heat 

 measured 



(small 

 calories). 



(/)X1000. (g)^(c) 



Small 

 calories 



per 

 second. 



20-39 

 20-44 

 20-51 

 20-53 

 20-64 

 20-56 

 20-58 

 2050 

 20-56 



o 



4-73 

 4-74 

 4-77 

 4-83 

 492 

 4-99 

 4-94 

 4-95 

 4-99 



4730 

 4740 

 4770 

 4830 

 4920 

 4990 

 4940 

 4950 

 4990 



2-947 

 2-917 

 2-935 

 2-945 

 2-937 

 2-970 

 3050 

 2-950 

 2-893 



(0 



Equivalent 



watts = 

 calories X J. 



(70x4-1972. 



12-37 

 12-24 

 12-32 

 12-36 

 12-33 

 12-47 

 12-79 

 12-33 

 12-14 



12-37 



Electromotive force =20*0 volts. 



Current=0-617 ampere. 



Watts (from electrical measurements) 



20-0x0-617= 12-34. 



4. The Experiments. 



Table II. (p. 230) give? the results of six experiments with 

 the same beeswax and rosin condensers which were employed 

 in onr work by the resonance method. In each experiment a 

 preliminary run, not included in the table, allows the condensers 

 and calorimeter to come to a constant temperature. Column 

 (a) gives the numbers of the condensers in each case, they all 

 being joined in parallel to the same electromotive force. 

 Column (b) gives the time of the beginning of each litre of 

 water; column (c) the duration of each litre or 1000 grammes 

 of water; column (d) the average temperature of the ingoing- 

 water as found from readings of the thermometer E, taken 

 regularly every five minutes, and column (e) the same for the 

 outgoing wafer; (/) then shows the increase of temperature. 

 Column (g) gives the number of calories of heat carried away 

 by each 1000 grammes of water, and column (Ji), which is the 

 number in (g) divided by the corresponding number of seconds 

 recorded in (c), is the rate of absorption of heat. Column (i) 

 gives the number of watts to which this is equivalent, taking 



