TABLE 383.— PELTIER AND THOMSON HEATS; PRESSURE EFFECTS 383 



The following data indicate the magnitude of the effect of pressure on the Peltier and Thomson 

 heats. They refer to the same samples as for the last table. The Peltier heat is considered positive 

 if heat is absorbed by the positive current from the surroundings on flowing from uncompressed 

 to compressed metal. A positive d 2 E/dt* means a larger Thomson heat in the compressed metal, 

 and the Thomson heat is itself considered positive if heat is absorbed by the positive current in 

 flowing from cold to hot metal. Same reference as footnote 141, and notes as for preceding table. 



TABLE 384.— THERMAL ELECTROMOTIVE FORCE OF CADMIUM VERSUS 



PLATINUM 



Temperature versus emf 



TABLE 385.— PELTIER EFFECT 



The coefficient of Peltier effect may be calculated from the constants A and B of Table 

 377, as there shown. With Q (see Table 377) in microvolts per °C and T = absolute tem- 



perature (K), the coefficient of Peltier effect = 



QT 



42 



cal per coulomb = 0.00086 QT cal 



per ampere-hour = 07/1000 millivolts (= millijoules per coulomb). Experimental results, 

 expressed in slightly different units are here given. The figures are for the heat produc- 

 tion at a junction of copper and the metal named in calories per ampere-hour. The current 

 flowing from copper to the metal named, a positive sign indicates a warming of the 

 junction. 



Calories per ampere-hour 



Sb 



Sb com- 

 mercial t Bi pure 



Bit Cd 



- —.62 



German 

 silver Fe Ni 



— —3.61 4.36 



Pt Ag 



.32 —.41 



13.02 4.8 



19.1 



25.8 



.46 



2.47 



2.5 



Zn 



-.58 



— - — .39 



* Becquerel's antimony is 806 parts Sb + 406 parts Zn + 121 parts Bi. 

 t Becquerel's bismuth is 10 parts Bi + 1 part Sb. 



SMITHSONIAN PHYSICAL TABLES 



