wiLLiAir .sy/-:.i//;.\.v, F.R.S. 247 



domestic fuel ? The reasons are twofold ; coke is most difficult 

 to light, und when lighted looks cheerless without the lively 

 tlirki-ring flame. 



The true solution consists, I venture to submit, in the combined 

 application of solid and gaseous fuel brought thoroughly under 

 control, by first separating these two constituents of coal. I am 

 bold enough to go so far as to say that raw coal should not be 

 used as fuel for any purpose whatsoever, and that the first step 

 toward the judicious and economic production of heat is the gas 

 retort or gas producer, in which coal is converted either entirely 

 into gas, or into gas and coke, as is the case at our ordinary gas 

 works. 



"When in the early part of the present winter London was 

 visited by one of its densest fogs, many minds were directed 

 towards finding a remedy for such a state of things. In my own 

 case it has resulted in an arrangement of fire-grate which has met 

 with a considerable amount of favour and practical success (there 

 being some two hundred now in operation), and I do not hesitate 

 to recommend it to you also for adoption. 



One arrangement of this grate is represented in Figure 1, Plate 5. 

 The iron dead plate c is riveted to a stout copper plate a facing 

 the back of the fire-grate, and extending five inches both upwards 

 and downwards from the point of junction. The dead plate c 

 stops short about an inch behind the bottom bar of the grate to 

 make room for a half-inch gas-pipe /, which is perforated with 

 holes of about one-sixteenth of an inch diameter placed at distances 

 of one and a half inch along the inner side of its upper surface, 

 at an angle of about 50 from the vertical. This pipe rests upon 

 a lower plate d, which is bent downwards towards the back so as 

 to provide a vertical and horizontal channel of about one inch in 

 breadth between the two plates. A trap-door e, held up by a 

 spring, or counterweight, is provided for the discharge of ashes 

 falling into the horizontal channel. The vertical channel is 

 occupied by a strip of sheet copper b about four inches deep, bent 

 in and out like a lady's frill and riveted to the copper back piece. 

 Copper being an excellent conductor of heat, and this piece pre- 

 senting (if not less than a quarter of an inch thick) a considerable 

 sectional conductive area, transfers the heat from the back of the 

 grate to the frill-work in the vertical channel. An air current is 



