1903.] Specific Heats, especially at Low Temperatures. 



177 



" On the Determination of Specific Heats, especially at Low 

 Temperatures." By H. E. SCHMITZ, M.A., B.Sc. Com- 

 municated by ARTHUR SCHUSTER, F.RS. Received Febru- 

 ary 2, Read February 19 Received in revised form 

 June 3, 1903. 



The specific heats at low temperatures of various metals have recently 

 been determined by Professor Tilden,* by U. Behn,f and by 

 C. C. Trowbridge.J In the following table are given the values 

 obtained by Tilden and by Trowbridge, and some of the numbers 

 obtained by Behn ; the numbers given represent the mean specific 

 heats between the temperature of liquid air or of liquid oxygen and 

 the atmospheric temperature. 



The differences in the method of cooling the metal probably furnish 

 a partial explanation of the discrepancies here shown. Tilden used a 

 portable metallic air chamber cooled by means of liquid oxygen, and 

 assumed the initial temperature to be - 182 -5. Behn used a fixed glass 

 air chamber cooled by means of liquid air ; the initial temperature was 

 assumed to be that of the liquid air, which was measured by means of 

 a thermo-electric couple. Trowbridge immersed the object directly in 

 liquid air which had been boiling for some time, and assumed the 

 initial temperature to be 181'5. 



The author of the present paper has made a series of determinations 

 of the specific heats of several metals (i) between the temperature of 

 liquid air and the atmospheric temperature (ii) for the ordinary 

 temperature range, 100 to 20. In the former case he has used two 

 distinct methods, one being the method of mixtures. In the latter case 

 he has used only the method of mixtures. The experiments were 

 conducted mainly in the physical laboratory of the Owens College, 



* 'Phil. Trans.,' A, J900, vol. 194, pp. 2i6 250. 



f < Wied. Ann.,' 189S, vol. (,6, p. 237; also 1900, vol. 1, p. 257. 



J ' Science,' 1898, vol. 8, p. 6, quoted in ' Science Abstracts/ 1898, Xo. 1325. 



