74 ANNUAL OF SCIENTIFIC DISCOVERY. 



lighted, instantly ignited the cinders above, and at the same time the pitchy 

 vapor from the fresh coal beneath rose through the wood flame and cin- 

 ders, and became heated sufficiently to inflame itself, and so to augment 

 the blaze. "When the cinder was once fairly ignited, all the bitumen rising 

 through it afterwards became gas, and the fire remained quite smokeless 

 for the remainder of the day. In this grate no air was allowed to enter at 

 the bottom, and combustion therefore only went on between the bars. 

 The unsatisfactory results of some other attempts had been owing, in part, 

 to combustion proceeding downwards, owing to the admission of air 

 below. 



ON THE CONSUMPTION OF FUEL AND THE PREVENTION OF SMOKE. 



At the British Association, Mr. Fairbairn, in a communication 011 the 

 above subject, explained the principles on which the perfect combustion 

 of fuel depends, and expressed his opinion that by proper attention, and 

 by the adoption of the means already known ard practised, the issuing of 

 smoke from steam-boiler furnaces might be effectually prevented. The 

 great secret is to have sufficient capacity in the boiler ; and if the boilers 

 had double their usual capacity, the perfect combustion of the fuel, and, 

 consequently, the prevention of smoke, might be readily accomplished. 

 He referred to the steam-engine furnaces of the Cornish mines to prove 

 that when there is a sufficient inducement to the proprietors by the saving 

 of expense, and of incitement to the engineers by competition, the emis- 

 sion of smoke is prevented without any special arrangement to produce 

 that effect. Mr. Fairbairn then described a furnace which he conceived 

 offered great facilities for the more perfect combustion of fuel. It consists 

 of two furnaces united into one, the gases issuing from the coals being 

 mixed together in a single chamber, and then passed in a heated state over 

 the bridge of the furnace, where they are ignited. By this means, and by 

 kepping the fire-bars clean for the admission of air, the combustion was 

 rendered very complete. 



An improvement in smoke-consuming stoves has been made by E. A. 

 Hill, of Joliet, Illinois. The fire-box of the stove is divided into two 

 compartments, each having a separate smoke pipe, and both fire-places so 

 connected together that the smoke from one can be thrown over the sur- 

 face of the other fire alternately by a damper, so that the products of the 

 combustion of both fires pass up the same pipe. For burning bituminous 

 coal, the improvement appears to be an excellent one ; for it is designed 

 that one of the fires shall always be full, red and glowing, when the other 

 is supplied with fresh fuel, so that the black smoke (carbonic oxide) which 

 arises when new coals are put on shall be carried over the top of the 

 glowing fire, and mixed with a portion of fresh-heated air, by which 

 means it will ignite flame up and be consumed ; in other words, form 

 carbonic acid. This stove will not only consume the smoke, but save 

 considerable fuel. Scientific American, 



