322 Dr. W. T. David on Heat-loss by Conduction 



of^ maximum temperature (2050° C. abs.), which occurs in 

 this mixture at 0*08, sec. after ignition, the heat-loss by 

 conduction amounts to # 17 calorie per sq. cm., of which 

 about 0*14 calorie is in the silver grid and about 0'03 calorie 

 has passed into the linoleum backing. At 0*25 sec. after 

 ignition, when the gas temperature has fallen to 1700° O. abs. r 

 the conduction loss is 0*67 calorie per sq. cm., of which 

 0*43 calorie is in the silver and 0*24 calorie has passed into 

 the backing. 



Similar experiments were made upon 15 per cent, and 

 9*7 per cent, mixtures of coal-gas and air. The results are 

 given in fig. 3. Those for the 12*4 per cent, mixture are 



Fig. 3. 



<J 1600 

 I 





* k 



5 J20O 





to <b 

 ^0-2 



/ 



s^ 























>> 









K 











\ / 



> 



> 



< 



==^ 















/ 



' 



r.< 













1 



/ ^ 



/ 







% 



^ 









k 



A 







-««^ 



r* 











7 



r j 









*~ — -5. 



"*--*.-«u-« 









4, 









:■«-==• s 



005 01 



0-15 0-2 0-25 



Time after ignition — 



3 0-35 



Sees. 



0-45 0-5 



12. 



»'£ 



^ k 



4-V. U 

 O t 



O 



Curves showing Heat-loss by Conduction per sq. cm. of Wall-surface 

 in 15"0 per cent., 12-4 per cent., and 9*7 per cent, mixtures of Coal- 

 gas and. Air. 



also given for purposes of comparison. The T-curves give 

 the mean gas temperature in the different mixtures at various 

 times after ignition. The C-curves give the heat-loss by 

 conduction per sq. cm. of wall-surface ; and the dotted 

 C'-curves give the rate of heat-loss by conduction per sq. cm. 

 per sec. Tables II., III., and IY. have been compiled from 



