J38 Miscellaneous Intelligence, 



people also are more willing to come to work, having warm work- 

 shops to come to. The method has the merit of being a very- 

 safe one. 



The cotton-mill warmed contains five rooms, the four upper 

 of wliich are supplied with warm air by the means described. 

 The rooms are fifty feet long by twenty broad : the general tem- 

 perature is said to be about 80° Fah. The kiln is called a small 

 one, being eleven feet deep, seven feet greatest diameter. It is 

 fed vidth limestone and fuel by a door in its cover, and is drawn 

 twice in 24 hours. If a very steady heat be required, it is re- 

 commended to be drawn three or four times in 24 hours. 



Where lime may not be wanted, the burning of bricks or tiles, 

 or even clay for manure, is suggested, as admitting of the same 

 arrangement. — Trans. Soc. Arts^ xlii. 134. 



8. Method of consuming the Smoke of Steam-boiler Furnaces, &c., 

 by Mr. Chapman. — Mr. Chapman's process consists in the intro- 

 duction of air into the furnace beyond the fire ; but he uses 

 peculiar means of heating this air before it is introduced, and this 

 renders the combustion of the smoke more ready and perfect. 

 He says, " To heat the air before its admission into the furnace. 

 This I do by casting the grate-bars hollow from end to end, 

 so that they form a series of parallel tubes, which open into two 

 boxes, one placed in front, and the other behind the grate. In 

 the front box, directly underneath the fire-door, I make a register 

 to open and shut, to any extent, at pleasure. The other end I 

 connect with the brick-work directly under the fire-bridge, which 

 fire-bridge I make double, with a small interval between, say one 

 inch ; the interval to go across the furnace from side to side, 

 and rather to incline forward, or toward the fire-door, so as to 

 meet and reverberate the smoke on to the ignited fuel in the 

 grate, which causes it to inflame and become a sheet of bright fire 

 under the bottom of the boiler." Consequently when the register 

 is open, air passes along the bars of the grate, becomes heated in 

 its passage, and is then thrown on to the hot smoke, causing its 

 inflammation and combustion. 



Mr. Chapman found that though his plan answered perfectly 

 when the fire-door was closed, yet it was inefficient when the 

 door was opened for the introduction of coals, so much cold air 

 passing in as to prevent the due effect of the arrangement. To 

 obviate this, he fed his fire with fuel in a diff'erent manner. " I 

 adopted a cast-iron hopper above the fire-door, with a type at the 

 bottom that has two pivots on one side, and opens at the other ; 

 one pivot goes through the end of the hopper, and has a counter- 

 lever to keep the type shut, when a sufficient quantity of coal 

 for a charge is on it. The top of the hopper is covered Avith a lid, 

 which I shut down during the time of firing ; then, by lifting the 



