Mode of heating by hot Water. 203 



This table shows an average heat of about 23° ; consumino-, 

 m the eight days, only 12 bushels of cinders, which cost lis. 

 per chaldron: being Ss. 8d. for the eight days, or 5^d. for 

 each twenty-four hours. Another experiment was made 

 just previously to the above, and the following was the re- 

 sult : — From the 'ith of March to the 1 9th, inclusive, being 

 16 days, the average heat was 23°, and 18 bushels of cinders 

 were consumed ; which is a fraction more than 4;d. per day. 



The second objection is that which you state yourself as 

 likely to occur ; viz. that, after a time, the tubes will become 

 lined with deposit, and difficult to heat. This I can also 

 prove to be erroneous, as far as it is applicable to my appa- 

 ratus, from reason and fact. The reason that my apparatus 

 is not likely to fill up is simply this : that its principle of 

 being kept closed in all its parts, so that no evaporation can 

 take place, is diametrically opposed to the cause of deposit. 

 This is strongly exemplified when any portion of water 

 escapes through an imperfect joint ; for, if the tube be hot 

 enough to evaporate the water, the deposit will be precipitated 

 on the outside of the tube ; showing clearly that the lime or 

 other matter which is in the water is held in solution until it 

 escapes to the outside. In fact, we have circulated, for months, 

 water completely saturated with salt, without any deposit 

 being formed. Another fact, which I will state, will, perhaps, 

 serve to remove your doubts, if any remain after the above 

 explanation. I erected, in the show-room of Messrs. Ive 

 and Burbidge, Fleet Street, last winter, an apparatus, con- 

 sisting of 150 ft. of tubing, of the dimensions of only one 

 fourth of an inch internal diameter, which has been at work 

 ever since, without the least appearance of deterioration, 

 either from oxidation, sediment, or otherwise. Were it 

 necessary, I could mention many other instances ; but I shall 

 content myself with one. 



One of Mr. Palmer's vineries contains an apparatus of 

 400 ft., of three-quarter tubing, which was kept in operation 

 last winter for the purpose of forcing grapes. At the end of 

 the winter we opened it, and found that not a drop of water 

 had evaporated or disappeared in any way ; and, upon wash- 

 ing it out, the water was as clear as when put in. I should 

 observe here, that the apparatus was worked a few days before 

 commencing to force ; and that, then, all the oil and other 

 matters, which necessarily adhere to the tubes during their 

 manufacture, being taken up by the water, it was drawn off, 

 and the pipes were washed out thoroughly by a common gar- 

 den engine, in order that the experiment might be complete. 



The third objection is, that the coil of tubes in the furnace, 



