1880.] 



on Invcstlgntions at Tliyh Teinpcratnrcs. 



2G5 



at constant temperature is caused to circulate, as represented in 

 Fig. '1, where KF represents the section of the vessel, and CD a largo 

 water screen, on the same plan, each having a narrow opening, about 

 half an inch in diameter, through which the radiant heat passed to 

 the pile, have confirmed the earlier results. The vessel holding tho 



Fig 



mercury or other substance to be heated to different temperatures has 

 a radiating face, which was made of the sheet iron used in the con- 

 struction of telephone plates, and tho thermometer must be placed 

 close to the back of the front surface, and the face guarded with a 

 screen, FG. The tube, CE, is connected with a condenser, when 

 substances at their boiling point are employed for giving fixed points. 

 The form of the apparatus is shown in Fig. 6. 



Fig. 5. 



This arrangement of the apparatus is necessary in order to get 

 anything like comparable results. The two following tables give tlic 

 records of two series of experiments, without any correction being 



