AND CONSKHVATOl^T, 21 



circulation. It is common in stoves where a moist boat is re- 

 quired to place several feed cisterns over the flow-pipe to 

 promote evaporation. It only needs to here mention that 

 " water will find its level " to render all these considerations as 

 simple as A B C, and, whether or no, the recognition of this 

 law of nature is the essence of hot-water engineering. 



In the adoption of pipes, those of one or two-inch bore are 

 adapted for small houses, and for subsidiary systems in heat- 

 ing parts of houses, such as propagating compartments. But 

 the teachings of experience are all in favour of four-inch pipes 

 for all ordinary purposes, and of two-incli or three-inch pipes 

 for any part of a system where the heat has simply to be con- 

 veyed and not diffused, as in the intervals between houses that 

 are heated from the same boiler. In the fitting of the pipes 

 there is nothing so good and cheap as rings of india rubber, 

 which are placed over the end of each length, and then driven 

 with it into the socket. If these are of the right size and tlie 

 pipes are properly forced home with the rings, &c., there is no 

 occasion for cement or any kind of waterproof stopping. 

 There may be a leakage here and there for a week or so, but 

 it will cease without requiring help, and the joints will keep 

 for a lifetime. 



In setting boilers of all kinds the size of the flues must be 

 regulated according to the fuel to be employed. If coal is to be 

 used they should be half a size larger than would be desirable 

 for coke, or they will be soon choked up with soot. The pipes 

 should be laid above the level in all cases, if possible, for if 

 they dip anywhere, as, for example, to pass under a doorway or 

 a path, there will be great loss of heat, and it will be impossible 

 to get up a heat quickly. Have plenty of piping, for there is 

 no economy in a stint. In setting a saddle it is well to place 

 it on a row of fire bricks, to afford more space for fuel. Tliis is 

 especially necessary when the fire has to be made up to last 

 some time. " Driving" is a detestable practice, and should 

 only be resorted to in emergencies. A large steady fire is far 

 more economical as to consumption of fuel than a small fire 

 with a quick draught, for the stronger the draught the greater 

 the quantity of cold air from without, as well as water within. 

 to be heated. Careful stoking is required for all tubular 

 boilers, on account of the exposure of the tubes to the fire ; 

 hence, in a place where things are done roughly, the saddle 

 form is to be preferred. 



