HEATING BY HOT- WATER PIPES. 



155 



mode did not give the rapidity of motion 

 to the water which some others do, it has 

 the advantage of never getting out of 

 order ; and the boiler being open at top, 

 admits of its being cleaned out as often 

 as is desired, without either trouble or 

 expense. For a very great majority of 

 situations this mode of heating is admir- 

 ably adapted ; and indeed, wherever it 

 can be employed, it has not been super- 

 seded. Intimate as we were with Mr 

 Atkinson — so much so, indeed, that we were 

 privy, along with the late Mr Tredgold, Mr 

 Barrow, and Mr Turner, to all his experi- 

 ments long before they were made known 

 to the public — we never saw his boilers 

 furnished with a waste-pipe for emptying 

 them of their contents, a precaution that 

 should never be neglected, more especially 

 where close-topped boilers are used. 



We have thirteen arrangements of 

 apparatus upon the horizontal principle 

 in operation in the Dalkeith gardens, and 

 we are quite satisfied with them — as much 

 so, indeed, as with any other of the many 

 in use in the same establishment. 



Bacon's original apparatus consisted 

 merely of a single cast-iron pipe, which, 

 so far as we recollect at this distance of 

 time — having seen it at work in his garden 

 at Aberdere in Glamorganshire, in 1828 

 — was about 9 inches in diameter. One 

 end of the pipe was placed in the fire, and 

 it was closed at the other; an upright piece 

 of pipe was attached to it about 18 inches 

 from the end, and rising about 6 inches 

 above it. The result, as may be expected, 

 was an immense waste of fuel and little 

 or no circulation. Mr Bacon afterwards 

 Fig. 163. adopted Mr 



° Atkinson's 

 principle. 

 i The annexed 

 ~~ sketch, fig. 



163, will give 

 a perfect idea of Mr Bacon's apparatus. 



Kewley, whose system was upon the 

 siphon principle, was the next whobrought 

 into operation any really useful improve- 

 ment, because he increased the circula- 

 tion to a more rapid rate than that secured 

 by the horizontal method, and the ex- 

 traction and delivery of heat consequently 

 became greater in proportion to the 

 quantity of fuel consumed — the water 

 never being heated to the extent to gene- 

 rate steam, nor the heated air and smoke 



which escapes by the chimney-top being 

 nearly so hot as when water is brought 

 to the boiling point, and often much 

 higher. This latter remark does not, 

 however, apply to the horizontal prin- 

 ciple, as, if all is properly arranged and con- 

 ducted, no steam should in it be generated. 



Fig. 164. The an- 



nexed di- 

 a g r a m, 

 fig. 164, 

 will show 

 the ope- 

 ration of 



Kewley's principle. The boiler is open 

 top, the upper or flow-pipe 

 a few inches below the 

 when the appa- 



5 



at the top, the 

 dipping only a few 

 surface of the water 

 ratus is filled, the lower or return pipe 

 descending to nearly the bottom of the 

 boiler. A small tube is inserted in the 

 top of the upper pipe where it turns at 

 a, (and this point must always be the 

 highest that the pipe attains to,) for the 

 purpose of extracting the air from the 

 pipe by means of an air-pump, without 

 which precaution the water would not 

 circulate. As the water in the boiler is 

 hottest nearest the surface, it follows that 

 the heated particles will much sooner 

 flow into the upper pipe than into the 

 longer and under one, which receives only 

 the less heated particles, and those only 

 which rise immediately under its base. The 

 circulation here is governed by the same 

 laws as elsewhere stated, {vide Cause op 

 Circulation ;) as the water flows along, it 

 gives out its heat, and as it returns to the 

 boiler it becomes colder and more in- 

 creased in gravity, causing it to flow into 

 the boiler with greater force. 



It has been suggested, and with good 

 reason, that if this long or return pipe 

 were made to pass down the outside 

 instead of the inside of the boiler, the 

 circulation would be increased ; and the 

 only objection to this plan is the greater 

 difficulty of stopping the ends of the pipes, 

 which in this system is done by having 

 two plates of iron so contrived that they 

 can be screwed closely enough to the 

 mouths of the pipes, as not only to exclude 

 the water, but also to resist the air when 

 forced against them when the air-pump 

 is applied, to prove the soundness of the 

 joints. 



Mr Kewley long made a sort of mystery 



