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MR. W. T. DAVID ON THE RADIATION IN 



very nearly the same. Those with the 15-per-cent. mixtures (second series) and 

 13-per-cent. mixtures were made about a fortnight later, during which time the 

 calorific value of the gas had probably increased slightly. 



The following tables have been prepared from the curves in this figure. The third 

 column in each table gives the average loss of heat by radiation per sq. cm. of wall 

 surface (assuming that the mean value of the radiation per sq. cm. measured in 

 positions A, B, and C is the same as that over the entire surface of the vessel) at 

 various times after ignition. The figures in the fourth column show the total heat 

 lost by radiation, at the various times from ignition given in the first column, 

 per cent, of the heat of combustion of the coal-gas present in the vessel. 



The calorific value of the coal-gas is taken at 320 pounds Centigrade units (lower 

 value), equivalent to 145,000 calories per standard cubic foot. 



Volume of vessel, 0788 cub. ft. 



Area of interior surface of vessel, 4380 sq. cm. 



TABLE I. 9'8-per-cent. Mixture. Initial Pressure, Atmospheric. 

 Heat of Combustion of Coal-gas present in Vessel = 10,600 Calories. 



TABLE II. 15-per-cent. Mixtures (First Set). Initial Pressure, Atmospheric. 

 Heat of Combustion of Coal-gas present in Vessel = 16,200 Calories. 



