Table 338 



HEAT LOSSES FROM INCANDESCENT FILAMENTS 



329 



(a) Wires of Platinum Sponge Served as Radiators to Room-temperature Sur- 

 roundings, Hartman, Physical Review, 7, p. 431, 1916 



Diameter 

 wire, 

 cm. 



o . 0690 

 0.0420 

 0.027s 

 0.0194 



(A) Observed heat losses in watts per cm. 



Absolute temperatures. 



1.70 

 1-35 

 1 . 12 

 0.92 



2.26 

 1-75 



1.40 



4.92 



3-53 

 2-73 

 2.12 



1400 



6.18 



4.29 

 3.23 

 2-54 



1500 



7.70 

 5-33 

 301 



3-04 



1600 



903 

 6.60 

 4.67 

 364 



12.15 

 8.2s 

 5-72 

 4-32 



15 33 



10. 20 



7.00 



5 10 



19 25 



12.4s 

 8.64 

 6. 10 



23-75 

 M-7S 

 IO-45 

 7-35 



(B) Heat losses corrected for radiation, watts per cm (A-C). 



o . 0690 

 0.0420 

 0.0275 

 0.0194 



(C) Computed radiation, watts per cm, a = 5.61 X 10 12 .* 



0.0690 

 0.0420 

 0.0275 

 0.019s 



7-7S 

 5-47 



(D) Conduction loss by silver leads, watts per cm. 



0.0420 

 0.0275 

 0.0195 



(E) Convection loss by air, watts per cm. 



; This value is lower than the presently (1919) accepted value of 5.72. 



(b) Wires of Bright Platinum 40-50 Cm Long Served as Radiators to Surroundings 

 at 300 K. Langmuir, Physical Review, 34, p. 401, 191 2 



Smithsonian Tables. 



