KX PLOSIONS OF COAI^GAS AND AIR. 



383 



centre of tl ml rover (position C) is alioiit .VI <-alories per sq. cm. per second, at the 



t-.|i (position A) it is 4'85 calories, and at the bottom (position B) it is 475 calorics, 

 at a slightly lower maximum temperature. As cooling proceeds the centre still 

 continues to receive more radiation than either the top or bottom parts of the end 

 rover, and the top more than the bottom, until the gas temperature falls to about 

 1 800 C. (abs.), when every part of the end cover seems to be receiving radiation at 

 approximately the same rate and continues to do so until a temperature of something 

 like 1300 C. (al.) is reached. After this the top receives more radiation than either 

 the centre or bottom and the centre more than the bottom, owing to the hot gas at 

 the top of the vessel emitting more powerfully than the colder gas at the bottom of 

 the vessel. 



In fig. 8, Curves I. and III. show the results of later experiments made with 15-per- 

 cent, mixtures and 13-per-cent. mixtures respectively, and Curves II. and IV. show 

 the results of the previous experiments made with 15-per-cent. mixtures and !)'8-per- 



I! 



" I* 



^ j< 



zcw t-o 



/600 -8 



(SCO 



800 4 



400 



offtr Tyni//on - 



Fig. 8. 



cent, mixtures (from figs. 4 and G). The Curves H refer to experiments made with a 

 i'. r )'4-per-cent. mixture of hydrogen and air (see p. 392). The radiation curves in this 

 figure are the means of those taken with the bolometer in positions A, B, and C. 

 The corresponding gas-temperature curves are also shown. The experiments with the 

 9'8-per-cent. mixtures and 15-per-cent. mixtures (first series) were made within a 

 week of each other, during which time the calorific value of the coal-gas was probably 



Curves!^ 15% mixfures (second ser/ti ) 



Cf/nf scr/'et ) 

 ~ t<5"/o Wx&rct 



Curves HE. 9-8% frmi /arcs ffrom ^ 

 CvrresH. -25-4%mMurts <f ffych-oye n v.rfir. 



