HEATING BY HOT- WATER PIPES. 



179 



Fig. 228. 



several in the gardens here, and find 

 them to answer all our expectations, except- 

 ing as regards 

 durability, in 

 which respect 

 experience has 

 taught us to 

 prefer cast- 

 iron ones — 

 still, however, 

 retaining the 

 saddle-backed 

 or arched form, which has many ad- 

 vantages over all others. Mr Glen- 

 dinning has recently very correctly 

 stated, in the "Journal of the London 

 Horticultural Society," that this form, 

 although one of our oldest, has merits 

 which would have made it wise " had we 

 endeavoured to improve it, — if, indeed, 

 it is capable of improvement. The arched 

 boiler," he observes, " is at once simple in 

 shape, of efficient power and easy applica- 

 tion. No boiler hitherto contrived so 

 perfectly combines these important points, 

 for, while it is possible to get up a boiler 

 with more heating surface, there has in- 

 variably arisen some corresponding dis- 

 advantage." In principle they differ 

 little from those of Cottam and Hallen's, 

 and the Messrs Bailey's, already noticed. 

 Ours are either made water-tight at top, 

 by having the lid screwed down to the 

 top of the boiler, or left open when the 

 circulation is upon the horizontal prin- 

 ciple — the lid in this case being provided 

 with a flange all round, which fits loosely 

 into a groove round the top of the boiler, 

 and is rendered steam-proof, by filling the 

 groove with water before setting the flange 

 of the lid into it. Two short pieces a a, 

 or nozzles, are cast on the boiler, and to 

 these the pipes are secured. They are 

 set upon six fire-bricks, which allows the 

 heat to play around their sides, ends, and 

 top, as high as the bottom of the flow-pipe, 

 at which part they are covered over with 

 fire-tiles. The fire is made under them, 

 so that their concave bottom and sides 

 forms the sides and roof of the furnace. 

 They are thus completely enveloped in 

 heat ; and being narrow within, they soon 

 become heated, and also being from 3 to 

 4 feet in length, according to the heating 

 power required, they abstract a great 

 amount of heat from the fuel. 



Fowlers boiler. — Boilers upon the prin- 



Fio-. 229. 



ciple exhibited by fig. 229 have been 

 erected by Fowler of Temple Bar, London. 



a is the 

 fire-place or 

 oven ; b the 

 fire-bars or 

 grating ; c c 

 the roof of 

 the furnace 

 over the 

 boiler, built 

 with fire- 

 brick and 

 covered 

 with a stone 

 coping d d ; 

 e e are pipes 

 which go 

 round the 

 house and return in the usual manner ; /is 

 asinglepipe for givingsupplementaryheat, 

 or it may be wrought at the same time as 

 the others ; g waste or expansion pipe ; £lid 

 of the boiler. This boiler, like the last, 

 is well adapted for abstracting heat from 

 the fuel, being surrounded on all sides by 

 the fire. There is no pressure of building 

 upon it as in many others, but the pressure 

 of water upon it is considerable ; hence, 

 we need hardly say, the material and 

 workmanship must be of the best kind. 

 This boiler is also of malleable iron, and 

 longitudinal in shape, like a large drain- 

 tile, whose sides, like that used by our- 

 selves, (vide last diagram) form the 

 furnace. Those boilers, of whatever form, 

 which are not surrounded on one side by 

 water and the other by the fire, must 

 always have less or more fuel to waste. 

 Bailey s new boiler. — A very ingenious 

 t,. OQn and effective 



Flg> m boiler (figs. 230, 



f——— — • 231,232) has re- 

 cently been ma- 

 nufactured by 

 Messrs D. and 

 G. Bailey, High 

 Holborn, Lon- 

 don, one of 

 which was lately 

 pointed out to 

 us in the garden 

 of the London 

 Horticultural 

 Society, where 

 it has been some time in operation, and 

 has given satisfaction. The body of the 



