134 



THE ELECTRIC ARC 



flaming arc requires 0.144 watt per mean hemispherical 

 candle power, and the white flaming arc 0.338 watt. 

 Further data will be given in the tables at the end of this 

 chapter, but for an adequate knowledge of the photometry 

 of these lamps reference must be made to the articles con- 

 stantly appearing in the technical journals. 1 



50 



50 



60 



60" 



FIG. 43. 



Metal, Including Mercury, Arcs. As far as I have been 

 able to learn no measurements have been made on the 

 candle power of arcs between metals in air. 2 None of these 



1 See also Bloch, Elektrot. ZS., 30, 703; 1909. 



Georges, Elektrot. ZS., 30, 595; 1909. 



Heyck, Elec. World, 54, 863; 1909. 



Elektrot. ZS., 30, 1055; 1909. 



Monash, Elektrot. ZS., 30, 341; 1909. 



1 This does not include arcs having one terminal an oxide of metal such 

 as the magnetite arc. 



