62 



Retrospective Criticism. 



in my green-house) by liaving the pipes half or one tliird the size of those 

 used in the stove. 



Since writing the above, I found Mr. R. Evans (who made my apparatus 

 under my own immediate instructions, no one having beard of it in this 

 part of the country) had made a worliing model, which I have just seen 

 in operation ; and to satisfy himself th;tt my plan was correct, he had union 

 joints in the delivering pipe, and also in the returning pipe, so curved 

 that, when turned down, they were below the level of the bottom of the 

 boiler ; and the consequence was, the hot water was as much cut off as if 

 a stopcock had been in that part of the pipe; but as soon as the 

 bent pipe was brought up to a level, the heat proceeded forward im- 

 mediately. This is particularly satisfactory to me, as it proves the thing 

 most decidedly. 



a. Feeder, and to allow for the expansion of /, Reservoir. 



the water. " "' 



b. Stopcock in the top of the boiler, which 



serves as a guide to till the boiler. 



c. Boiler. 



d. Delivering pipe. 



e. Keturning pipe. 



g. Pipe connected with delivering pipe. 

 h. Pipe connected with returning pipe. 

 i. Pipe and funnel like a ; a loose cork is placed 



at the top of each. 

 j. Delivering pipe to the green-house|(B). 

 k. Returning pipe to the green. house. 



The whole apparatus is made of thin copper. The pipes in the stove (A) 

 are sin. diameter, and those of the green-house (B) If in. diameter. The 

 size of the boiler, 2 ft. diameter, and 1 ft. deep ; and the feeder («), 9 in. 

 high, and 2 in. diameter, so as to allow a thermometer to be introduced ; 

 the funnel, at the top, 6 in. diameter; the reservoir, 5 ft. long, 1 ft. 6 in. 

 wide, and 1 fit. deep. This apparatus will heat a stove of from 20 to 50 ft., 

 and a green-house of the same dimensions. 



I beg to apologise for this long communication, but perhaps to amateurs 

 like myself it may prove highly interesting and serviceable. With the hope 

 that it may be so, I am. Sir, &c. — Robert W. Byers. 15. Union Buildings, 

 Swansea, February 4. 1828. 



Since I sent you my letter of the 4th inst., on the hot water system, I have 

 been trying to account for the hot water not descending below the bottom 

 of the boiler, and my solution will, I think, be as satisfactory as it is short. 

 Hot water being specifically lighter than cold water, nothing but e.\tra- 

 ordinary pressure can force the hot water into a place that, by the law of 

 gravity, it could not occupy without such pressure. This pressure not being 

 used, the consequence is, hot water cannot descend below the source of 

 beat.— 7?. W. B. February 13. 1828. 



