ATMOSPHEEIC PRESSURE BETWEEN 104" C. AND 115 C. 



401 



measurement is made when the supply of electrical energy is cut off, and the difference 

 between these two temperatures gives the rise in temperature d6 of the steam. If 

 C t is the electric current and E! the potential difference between the ends of the heating 

 coil, we have, when the temperature conditions through the apparatus are steady, 



where h^dO is a term representing the heat-loss, and S is measured in joules per gr. 

 degree C. If now, in similar experiments, the rates of flow, Q, of the steam are about 

 one-half and one-quarter of the above value respectively, and if the electric current is 



To Fnm 



BURKtR BOILfK 



Fig. 4. 



adjusted in each experiment so that the rise in temperature of the steam is the same 



as before, we have p ^, 



and 



If the heat-loss is independent of the flow, a linear relationship will exist between the 

 values of CE/QcW and the corresponding values of 1/Q, but if this is not so, another 

 term depending on the flow must be inserted in the fundamental equation, which then 



1)60011168 CE . 8Qd6+(h+k/Q) de. 



By means of three equations of this form we can obtain the values of S, h, and k. 



3 H 3 



