By Mr. Thomas Tredgold. 



583 



combustion of the fuel perfect, and, consequently effective ; 

 hence, a fire-place surrounded on three sides by brick, is 

 better than one in the middle of the boiler. 



23. The best mode of regulating the fire, is by means of a 

 door to the ash-pit, having a register, first suggested by Dr. 

 Black, and afterwards put in practice by Count Rumford. 



24. I have now considered the most important points in 

 the construction of a hot-water apparatus, and have shown 

 that other fluids may be applied as well as water, when a 

 more intense heating surface is desirable ; and that a reservoir 

 of heat may be obtained without having to wait till a large 

 mass of water be heated before the heat has any effect on the 

 house ; and these I hope will be of some use in the applica- 

 tion of this method of distributing heat. 



I have the honour to be, 



Sir, your most obedient servant, 



To Joseph Sabine, Esq. THOMAS TREDGOLD. 



