62 



JOURNAL OF HOETICUIiTURE AND COTTAGE GAEDENEK. 



July 2S, 1863. 



would be providing the boiler was of an equal width through- 

 out. For instance : a cylinder with a base of 3 superficial 

 feet exijosed to the direct action of the fire will not heat so 

 soon as a conical boiler (supposing them both to hold the 

 same quantity of water), with a base of 6 feet. Another 

 reason why I would have the boilers wider at the bottom 

 than at the top is this — When an upright passage is pre- 

 pared for heat to pass through, it does so mthout parting 

 with much of its temperature ; whereas if the surface were 

 e!q)osed but inclined, the heat would run against it, as it 

 were, in its never-failing passage upwards, and it would 

 lose some of its temperature ivith ten times greater rapidity 

 by contact than by radiation in a hiu'ried passage. Every- 

 body knows that an upright chimney is never so hot as a 

 horizontal flue, the reason being heat ascends ; in the chimney 

 it is free, in the flue it is continually striving to ascend, and 

 burrs, so to speak, against the flue top its entire length, 

 consequently loses heat continually. In a boiler it is pretty 

 nearly the same. A saddle boiler loses almost all the heat 

 of the fire after its first contact with it, for when the flame 

 goes along the side or over the boiler the top of the flue is 

 heated more than the boiler. At the turns in the flue this 

 is hotter, because the ciuTent of hot aii' is checked by an 

 obstruction. 



Another reason why I prefer a boiler wider at the bottom 

 than at the top is, the cii-culation is more rapid. After 

 water is heated the sooner it passes into the pipes the 

 better, and the smaller the opening to admit the water from 

 the boiler into the pipes the more quickly will it pass into 

 them. By having the boiler top narrower than the bottom, 

 the water is compressed similarly to a swollen river pass- 

 ing thi'ough a bridge, and eveiybody knows the current is 

 stronger there than anj^wliere else. In a boiler, by heating 

 a large body at the bottom of the boOer, and then causing 

 it to pass through a naiTOw passage, we obtain double or 

 treble the velocity. Let any one doubting this connect a 

 piece of 1. J -inch pipe to the boiler-nozzle instead of a four- 

 inch, and he will find the hot water rush through it at six 

 times the speed that it does through a four-inch pipe. 



Water exposed to heat expands, becomes lighter, and 

 ascends, and the quicker we get it out of the boUer after it 

 is heated into the pipes the more heat we obtain . We do not 

 want boiling water in the boiler and cold water in the pipes : 

 therefore, the sooner hot water is replaced by cold water in 

 the boiler the more economical is our heating apparatus. 

 The water cannot come too freely into the boiler, it cannot 

 go too soon out. I infer from this that the water should 

 have double the space to come into the boiler as to get out. 



The 5th point resolves itself into this : A boiler covered 

 with soot and dust will not heat well. Upright flues are 

 not so liable to hold soot as horizontal flues, and where the 

 draught is quick the necessity to clean is not so great as 

 when the di-aught is sluggish. Boilers, the parts of wliich are 

 naiTow and set horizontally, are very troublesome to keep 

 clean, and when the flues have many bends more soot will 

 lodge. Dirty flues reduce the heating power one-third, or, 

 in other words, a clean flue will heat any surface one-third 

 more quickly than a dirty flue with the same amount of fuel. 



On the 6th point I may observe that many boilers are 

 expensive because they cannot be repaired. A cast-iron 

 boiler cast solid in one piece cannot well be repaired when 

 it is worn through or biu'st, but a wi'ought-iron one can. 

 Cast-iron boilers that cost ^£20 very often have defective 

 places in them, and when these give way there is no remedy 

 but a new one. This very often causes a serious loss to the 

 owner and more mortification than enough, for it is not 

 pleasant to sec an expensive boiler worthless because it has 

 a small worn place in it, or a crack that could, would the 

 material allow it, be repaired for a twentieth part of the cost 

 of a new boiler. It is quite possible to have a cast-iron 

 bottom rivetted to a ■^^TOught-i^on top. 



The 7th point will be obvious to all. The sooner a boiler, 

 or rather the water, becomes heated the better for meeting 

 emergencies consequent on a fickle climate, for at times 

 little heat may be requii-ed ; but on the sudden, without 

 previous warning, severe weather sets in and more heat is 

 wanted. The struetiu'e to be heated has been kept as cool 

 a.s circumstances will pei-mit to save fuel and for the well- 

 being of the subjects ; but there is a minimum temperature 

 allotted to all plants, and to subject them to one below this 



is injurious if not fatal : therefore the heating apparatus 

 should be capable of attaining a certain temperature before 

 the external temperature has reduced the internal tempera- 

 ture to a point when fire heat would be too late to secure the 

 safety of the inmates of the structure, besides the anxiety 

 of mind consequent on waiting whilst a boiler is heating, 

 and the mortification attendant on obsei-ving the tempera- 

 ture lower after the tire is started instead of heating sharply. 

 A slowly -heating boiler is more costly than a quickly -heating 

 boiler, but, of course, much depends on the draught. A 

 boiler heating slowly through a bad draught, and another 

 heating quickly with a strong di'aught, will be about equal 

 in cost. A boUer, therefore, ought to heat quickly without 

 wasting any heat or burning more fuel than a slowly-heating 

 boiler. 



The 8th point conveys its own meaning. A boiler should 

 be under control like a horse. It ought to keep the pipes 

 either warm or hot, and consume only half the fuel for the 

 former temperature than for the latter. 



Point the 9th is perhaps the most important. A boiler 

 that bums coke will be more costly than worthy where 

 coke is 21s. per ton, and other fuel can be had for 5s. per 

 ton and afford the same result. 



Such a construction as a universal boiler never has been, 

 and perhaps cannot be, manufactured. A boiler that will 

 heat readOy by wood would suit in some places, by coal at 

 another, and by coke at a third ; but a boUer that would 

 heat with a combination of each is much wanted. 



The 10th and 11th points are solely relating to economy. 

 Point 12th is well nigh impracticable. Neither is it 

 necessary to provide for the cleaning of a boUer from the 

 inside, for there is no steam in a boiler, therefore no 

 incrustation of the iron. No one ever, or veiy rarely, saw 

 any incrustation on a boUer or pan without a lid ; and in a 

 boiler closed from the external air and full of water little or 

 no incrustation takes place, providing the sediment re- 

 sulting from corrosion is let out before the jjarticles are 

 united to the boiler. BoOers are more liable to become 

 choked from corrosion and the lodgment of sediment in the 

 lower parts and the return-pipes than to become blocked- 

 up by incrustation. In fa«t, any boiler (I am not writing 

 about steam boilers) will be corroded through sooner than 

 choked by the incrustation resulting from the use of the 

 hardest water. Providing there is a hole drilled in a boiler 

 at its lowest point with a pipe protruding from the brick- 

 work and a tap, that is all that is required to clean a boiler. 

 — G. A. 



(To he continued.) 



JOTTINGS FROM PAEIS, 1863. 

 Ever since my return there has been one incessant round 

 of flower shows, and to chronicle these I have been compelled 

 to put on one side the few stray notes that I had made on 

 some of the notabilia in the gardening way which struck 

 me this year ; and as I have ever found that any informa- 

 tion to be obtained on the subject of Eoses could be had 

 from either the Verdiers or M. Margottin, I managed to 

 make a little trip to Bourg-la-Eeine, and have a couple of 

 hours' chat with as genuine a rosarian and as honest a man 

 as there is on either side of the channel. Unfortunately 

 I was nearly three weeks too soon to see anything in flower, 

 and was somewhat disappointed ; but I then learned what 

 perhaps I ought to have known before — that it is not in the 

 early spring that they ai-e so much before us, but as the 

 month of May advances ; and it brought to my mind what 

 struck me at the time as curious — that a gentleman who 

 kept a regular thermometric account of the temijerature at 

 different places, once told me that it was astonishing how 

 little difference there was between Paris, Lisbon, and his 

 own place up to the end of April, but that after that it 

 became very perceptible. Knowing that we have Eoses in 

 bloom in June I expected to find some at least in flower, 

 and was surprised to find that the buds were no farther 

 advanced than some in my own garden when I left home. 

 I was content then to have a view of one of the most beau- 

 tifully even lot of Eoses (as standards) that I ever saw, 

 and to have a good chat with my old friend and his amiable 

 son. 



