Petroleum Flames in various azimuths. 



53 



The following table gives the candle power of each flame at 

 azimuths differing by 5°. The photometric measures are the 

 mean of six series of experiments. 





Hitchcock 



Ordinary 





Hitchcock 



Ordinary 



Azimuth. 



flame. 



flame. 



Azimuth. 



flame. 



flame. 







9-8 



6-6 



50 



15-8 



10-25 



5 



12-25 



7-45 



55 



15-8 



10-35 



10 



13-5 



8-15 



60 



15-8 



104 



15 



14-3 



8-8 



65 



15-75 



10-44 



20 



14-8 



935 



70 



1565 



10-55 



25 



15-15 



9-65 



75 



15-6 



10-6 



30 



15-35 



9-85 



80 



15-6 



10-6 



35 



15-55 



10-0 



85 



15 6 



10-6 



40 



15-65 



10-1 



90 



15-6 



10-6 



45 



15-75 



10-2 

 n 10 . 1 



.-16 







-& 



14 



10 



h& 



Fl 



The flame of the Hitchcock lamp gives 15*6 candle power 

 in azimuth 90°, and only 9*8 candle in azimuth 0° ; that is, the 

 edge of the flame gives about 37 per cent less than the flat 

 surface. The flat flame of the ordinary petroleum lamp gives 



