﻿108 Messrs. H. T. Tizard and D. R. Pye on the 



values for the cooling factors so obtained are lower than 

 those found in the heptane experiments ; this would be 

 expected, for, although the specific heats of the mixtures are 

 about the same, the compression ratios used were lower in 

 the case of ether mixture than in the case of heptane, since 

 ether has a considerably lower ignition temperature. 



Table XI. 

 Calculation of cooling factor corresponding to D 2 . 



Time from 

 maximum 

 pressure. 



Observed 

 pressure. 



P - P /- 



p p 



, x max. *- f * 



log r-p, - =e - 



i 

 a =2-3 S/t.\ 







146-5 lb./sq. in. 



61-8 











•232 sec. 



129-5 



44-8 



•140 . 



1-39 



•465 „ 



118-4 



337 



•263 



1-30 



•70 „ 



109-5 



25-8 



•379 



1-25 



•93 „ 



103-6 



19-9 



•492 



1-22 



1*16 „ 



97-7 



130 



•677 



1-34 



1'39 „ 



96-2 



11-5 



•730 



1-21 



P f =5'73x 14-77=84-7 lb./sq. in. Mean = 1-28 



XIV. Taking the ignition temperature T (without fan) as 

 212° C. = 485 abs., the experimental observations of the delay 

 before ignition at higher temperatures are reproduced closely 



if the value of ^ =11. In this case, we have 



T -e _._ /212-23\ 



: 0-183. 



The theoretical values for "t" calculated according to 

 equation (11), are shown in the following table. 



Table XII. 



T/T . 



T. 



| 

 t°C. 



1-004 



487 



214 



1-01 



490 



217 



1-03 



499-5 



226-5 



1-07 



519 



246 



1-11 



538-5 



265-5 



127 



616 



343 



a(i^)^(theor.). 



•098 



•065 



•030 



•0105 



•0046 



•0004 



t (calc.). 



)535 sec. 

 •355 

 •164 

 •057 

 •025 

 •002 



