30 



MK. .T. H. CRIXDLKY OX AX EXPERIMENTAL 1NVKSTICATION OF 



mean specific heat at atmospheric pressure between 212 and 260 F., the data for 

 the calculations being obtained from REGNAULT'S experimental results.* ZuENERt 

 has also calculated the value 0'568 = K P by assuming a certain law of expansion to 

 hold in the superheated steam. 



The experiments of HIRN, however, afford under atmospheric pressure only a direct 

 comparison with those of the present research, as from the temperatures he obtained 

 by wiredrawing saturated steam from certain initial pressures to atmospheric pres- 

 sure it is possible to calculate by his formula quoted above the values of the specific 

 heat at atmospheric pressure between certain temperatures. The results have been 

 tabulated in Table VI., in which are also given the results of the present experiments. 

 This table is certainly very interesting, as it shows most clearly that a larger 

 variation exists in the value of K P as deduced from HIRN'S experiments than the 

 variation deduced from the present experiments. 



TABLE VI. On the values of the Specific Heat K, at atmospheric pressure as deduced 

 from HIRN'S experimental results and as calculated from the present experiments. 



Results calculated from HIRN'S experimental figures. 



Present Experiments. 



* MAC*ARLANE GRAY, ' Trans. Inst. Naval Arch.,' 1889. 

 t ZUWNER'S ' La Chaleur,' p. 441. 



