Petavel. 



Phil. Trans., A, vol. 191, 1898, Plate 22. 



Fig. 11. 





730 





iOO 6OO TOO iOO 3OO I.OOO l/OO 1200 WOO I,*OO I,i00 IJbOO 1,700 I.6OO 



Temperature in degrees CenCigra.de. 



Fig. 12. 



-\600 



4000 



l/OO " IfOO <30O 



Temperature in degrees Centigrade. 



