VARIOUS METHODS OF HEATING DESCRIBED IN DETAIL. 207 



the body of cold water flowing into the boiler, and the larger 

 the body of warm flowing from, it, the more heat is carried 

 away ; hence, the more specific caloric is required, and the more 

 combustion of fuel to produce it. But the proportion of fuel 

 consumed to the proportion of heat generated by the pipes is 

 found to decrease as the radiating surface is increased. This 

 decrease amounts to nearly one third ; for it is found that eight 

 separate houses, or departments of a house, can be heated by the 

 same quantity of fuel which it formerly required to heat five. 

 This calculation was supplied to me by an intelligent gardener, 

 of extensive experience, who made it from strict investigation 

 into the working of the system under his own charge ; and the 

 statement is corroborated by the fact, that no case has occurred, 

 to my knowledge, among many with which I am acquainted, and 

 have examined, that has failed to give satisfaction. 



This system has not the complex character which some have 

 assigned to it, and which, at first sight, it would appear to pos- 

 sess ; and, as to its cheapness, I believe little can be said about 

 it, when placed in comparison with other hot-water apparatuses. 

 I have had no means of calculating the difference, if any, 

 between this apparatus and as many single ones as it may be 

 substituted for. But it certainly appears, that four houses 

 heated with one boiler and one furnace, would be cheaper than 

 four houses heated with four distinct boilers and furnaces, the 

 quantity of piping in both cases being equal ; for then, three 

 boilers and furnaces, or the cost of them, would be saved. This 

 difTerence, however, will depend very much upon the distance 

 the pipes must travel before entering the different houses. 

 When the houses are situated close to each other, the difference 

 must be very considerable. Some apparatuses of this kind have 

 no box attached to them, and work directly to and from the boiler. 

 I consider the box, however, as a very important appendage ; 

 not only because it affords greater facility for working the 

 apparatus, but because any of the other arrangements may be 

 repaired more easily, and parts may even be taken away with- 

 out in the least affectinof the working: of the rest. 



As I have already stated, pipes, in reality, radiate a vjry dry 

 heat ; though many think otherwise, because the air of a hot- 



18=^ 



