Properties of High Temperature Flames. 

 Fig-. 1 {cont.*). 



807 



L u [| I M-M- l I I I I I I I JjJ 



1 2 3 4 5 



10 



15 



cms. 



^o 



It consisted of an electroscope in a cubical sheet zinc 

 case C, provided with an insulated charging-rod R. The 

 insulation o£ the electroscope was provided by the sealing- 

 wax sleeve S. A thermometer T, reading up to 30° C., 

 passed through the case and was fixed in position by paraffin- 

 wax. The case was provided with two windows of sheet 

 mica and a microscope with an eyepiece scale. 



The cover of the electroscope, L, consisted of a diaphragm 

 of thin metal mounted between two plates of zinc or card- 

 board for support. This cover and all joints in the case of 

 the electroscope were rendered air-tight by a thick layer 

 of paraffin-wax, thus precluding all possibility of ionized air 

 entering the electroscope. 



Temperature changes were guarded against by fitting a 

 cover provided with a jacket for circulating water over the 

 whole of the apparatus. This cover was painted dead black 

 inside, so as to diminish internal reflexion and prevent photo- 

 electric effects from disturbing- the test. 



The eyepiece scale was illuminated by a 16 c.p. electric 

 lamp placed about 5 feet from the apparatus. This lamp 

 was kept on throughout the tests, so that the illumination 

 inside the case was always the same. 



