J.[S THE ADDRESSES, LECTURES, ETC., OF 



set up by this heat, which, after passing along the horizontal 

 channel, impinges on the line of gas flames and greatly increases 

 tlioir brilliancy. So great is the heat imparted to the air by this 

 simple arrangement, that a piece of lead of about half a pound in 

 weight introduced through the trap-door into this channel melted 

 in five minutes, proving a temperature exceeding 619 Fahr. or 

 826 C. The abstraction of heat from the back has moreover the 

 advantage of retarding the combustion of the coke there while 

 promoting it in front of the grate. 



The sketch represents a fire-place at my office, in a room of 

 7, -00 cubic feet capacity facing the north. I always found it 

 difficult during cold weather to keep this room at 60 Fahr. with 

 a coal tire, but it has been easily maintained at that temperature 

 since the grate has been altered to the gas-coke grate just 

 described. 



In order to test the question of economy, the gas consumed in 

 the grate is passed through a Parkinson's 10-light r.ry gasmeter, 

 and the coke used is carefully \veighed. 



The result of 66 days' campaign of eight hours each, has been 

 a consumption of 4100 cubic feet of gas, 1112 Ibs. of coke and 

 581 Ibs. of smokeless coal (the fuel remaining in the grate being 

 in each case put to the debit of the following day). Calculating 

 the gas at the average London price of 8s. 6rf. per 1000 cubic feet, 

 the coke at 185. a ton, and the coal at 205. a ton, the account 

 stands thus : 



4100 cubic feet of gas at 85. 6tf. per thousand 



1112 Ibs. coke at 18*. a ton . . . . 



581 Ibs. smokeless coal at 20s. a ton .. 



Total . . 



or a cost of 0*518dL per hour. In its former condition as a coal- 

 grate the consumption exceeded generally two and a half large 

 scuttles a day, weighing 19 Ibs. each, or 47 Ibs. of coal, which at 

 28s. a ton equals 5.7rf. for nine hours, being 0'688rf. per hour. 

 This result shows that the coke-gas fire, as here described, is not 

 only a warmer but a cheaper fire than its predecessor ; with the 

 advantages in its favour that it is lit without necessitating the 



