Temperature of Inversion of the Joule-Kelvin Effect. 723 



from +300°. Above a certain temperature U the thermo- 

 couple showed a heating of the gas, below this temperature 

 an unmistakable cooling, and at the temperature t itself 

 the integral result of the Joule-Kelvin effect was zero. 



In the following table are given the initial pressures p 

 (expressed in kg. per sq. cm.) and the corresponding tem- 

 peratures of inversion U. 



Air. 



Nitrogen. 



P- 



tu 



P- 



tu 





o 





o 



160 



+259 



159 



4-243 



100 



249 



126 



238 



90 



244 



102 



233 



80 



240 



90 



228 



70 



235 



80 



223 



60 



226 



68 

 55 



217 



40 



193 



205 



20 



124 



30 



163 





























































160 

















































~rr z 







Jh 



R 



.. 















































J 





, 



J 





-150 

















































1 



































































ikO 









































































































1 







1 





430 















































1 







/ 



















































J 







/ 







no 





















































/ 



















































1 







/ 







>M0 















































1 







/ 

















































/ 







/ 









100 













































/ 







L 



















































/ 







/ 









90 











































J 







, 



i 

















































/ 

















go 









































./ 



/ 























































/ 



















70 







































/ 

























































A 





















60 





































/ 







„ / 



/ 















































y 







S 



y 

















50 

































y 







/- 



s 











































































W 















































































































30 

















































! 























































































































































































-130 



ilo 



150 



160 



no 



no 



190 



200 



240 



220 



230 



i 



iC 



250 



2£0 



In the accompanying figure the experimental results are 

 represented graphically, the initial pressures p (kg./sq. cm.) 



3 C2 



