Retrospective Criticism. Q\,- 



Art. VII. Retrospective Criticism, 



Hot Water in Pijjes helow the Level of the Boiler. — Sir, When the 

 Tenth Number of your valuable and very necessary Magazine arrived, I was 

 delighted with the process for heatihg stoves by hot water, and, without 

 delay, gave directions for the apparatus being made, which, with much 

 difficulty in putting up and pulling down several times (as detailed below), 

 at last rewarded me. 



My purpose in addressing you is to prevent others from adopting the 

 plan mentioned by you in the 190th page, in which you say, " if the height 

 which the water stands in the boiler and reservoir be equal, and as high as 

 the highest part of the pipes, the circulation between them will take place, 

 however low the pipes may descend." When I read this part of the sub- 

 ject, it seemed to me to be perfectly correct, and that it would not matter 

 how the pipes were placed, provided the water circulated on a level. 

 Accordingly, I bent my pipes so as to have them quite out of the way. (I 

 should previously remark, that I had tried the system for the sake of 

 proving the boiler and pipes, and found it to answer ; but the pipes were 

 then on a level: at that time I did not notice this most important fact.) 

 The pipes being thus adjusted, the mason's work finished, the whole filled 

 with water, and the fire burning well, judge of my disappointment when I 

 found I could not force the heat in four hours more than 4 ft. forward. I 

 kept up the fire, and the water boiled violently ; yet the heat did not ex- 

 tend, or extended but very little. I tried various experiments, but to no pur- 

 pose, and my stove was left that night much cooler than I could have wished. 

 The next day I raised what I term the delivering pipe, and the result grati- 

 fied me much, for, in ten or 12 minutes, the heat extended nearly through 

 the pipes on one side of the houge ; but it then began to decline, for from 

 that point the pipes descended to pass under the door of the stove. The 

 boiling commenced again in the boiler, but I could not force the heat for- 

 ward. The result was, that I was compelled to pull down mj^ masonry, and 

 bring the pipes (being now convinced that, if the pipes were in any part 

 lower than the bottom of the boiler, the circulation would not be perfect) to 

 a level with the bottom of the boiler. This was effected, and, in an hour after 

 the fire was lighted, I found my pipes, nearly 60 ft. in length, hot, the heat 

 proceeding from the delivering pipe towards the boiler by the returning 

 pipe. Being then satisfied as to the system, I found the heat not sufficient, 

 and again I had to pull the whole down, and added a reservoir, hoping that 

 the additional quantity of water contained in it would be sufficient ;;; but 

 the temperature of the house was still too low. Again it was taken down 

 (indeed twice more), and the pipes enlarged to 3 in. diameter in the 

 stove. These last alterations crowned my labours with success. I have 

 been thus minute in detailing my experiments, thinking it may show young 

 gardeners what a little perseverance will effect, and that nothing can be 

 expected without it, and also to urge every amateur and gardener to adopt 

 the system. Even were they to take as much pains as I have done in per- 

 fecting their object, they would be fully compensated for all their trouble, 

 as nothing can exceed the equal temperature produced by this highly 

 scientific and interesting mode of heating. 



The sketches {fig. 42.) I send, thinking they may be of some service to 

 those inclined to erect houses, and heat them on this principle. I think 

 three or even four houses might be heated with one boiler, by having a 

 reservoir in each house, and passing pipes, as in the sketches, from one reser- 

 voir to the other. Of course the houses would be cooler as their distance 

 from the fire-place increased, and this might be more perfectly effected (as 



