﻿Ignition of Gases by Sudden Compression. 113 



The cooling factor when the fan is used is 1*34. The ratio 

 of the loss of heat (or reaction velocity) at the ignition 

 temperatures with and without fan is consequently 



Qo' 1-34(296-42) 



Qo ~ 046(253-32) 



= 3-35. 



Hence the new ignition temperature T ' should be given by 

 the expression 



log3-35=0-525=£/T (l- ^ 



■(•-&)■ 



or 



^ =1-0-075 



= 0-925, 



T ' = 568-5 = 295°'5C. 



The new value of rfr7 corresponding to this is therefore 

 J-o 



v-'-(«w-** 



The calculation of the corresponding delay curve is shown 



° T , I being 



l-34xg=06. 



T/T . 



1004 



101 



1-03 



107 



1-11 



571 

 574 



585-5 

 6085 

 631 



Table XVII. 



t°c. 



298 

 301 

 312-5 

 335-5 



358 



a(^rr^(theor.). 



0205 

 015 



0-08 



0042 



0-025 



t (calc). 



'34 sec. 

 •25 „ 

 •13 „ 

 •07 „ 

 •04 „ 



This is the dotted curve shown in fig. 11, the experimental 

 points being marked as before. The agreement between 

 Phil May. S. 6. Vol. 44. No. 259. July 1922. I 



