1842.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



129 



I 



ON INCREASING THE EVAPORATIVE EFFECT OF BOILERS. 



Sir — In my communication inserted in the last Journal, I assure you I liad 

 no desire unnecessarily to occupy your useful columns, by " taking a range of 

 several months," in rcpljing to the very severe remarks of the reviewer of 

 my " projects." I trust, however, to your candour, in affording nie an oppor- 

 tunity of setting myself and my " projects" right with your readers, not as 

 1o the personal matter, but to the scientific and practical details of the 

 subject. Having disposed of the comments on my suggestions for increasing 

 the evaporative boilers, by means of longitudinal conductor plus, I now come 

 to that of the " smoke preventive plan." 



The reviewer observes — " Our philosopher says that combustion" (of the 

 gaseous matter from the coals) " does not take place (in the furnace), inas- 

 much as he has doors to his ash pit, which he shuts immediately that the 

 furnace has received a fresh charge, and which he keeps shut until the gas is 

 all expelled." To this I have only to say, it is entirely a gratuitous assump- 

 tion. I am guilty of no such absurdity. That I recommend doors to ash. 

 pits, as others have done before me, is true; not, however, for the sake of 

 excluding the air, or producing an '• hermetically sealed boiler furnace," but 

 of regulating its admission, as far as is practicable, to the ash pit and bars, the 

 doors being furnished with suitable slides or registers ; thus, in some measure 

 apportioning the quantity supplied to the demand, and where, in ordinary 

 furnaces, no attempt at any regulating means is made. The reviewer then 

 goes into a lengthened refutation of this manifest absurdity, which happens 

 to be exclusively the work of his own fertile invention ; and which I need not 

 further notice. 



He then observes — " -\11 smoke-burning projects operate upon the principle 

 cf admitting an excess of air into the furnace and flue, and this principle is 

 attended with two insuperable objections. First, the refrigeratory effect of 

 the great excess of air which it is necessary to admit to a mixture of the 

 gases, to accomplish the indispensable condition of combustion — proximity 

 of the atoms to be combined ; and second, the impracticability of apportion- 

 ing the admission of air to the ever-changing quantity of smoke evolved." 

 Now here are two important and clearly enuriciated terms ; and my reply 

 is, that it is expressly to correct these two evils that my plan applies, viz. the 

 preventing this refrigeratory effect, by rendering an " excess" of air unnecessary ; 

 and second, the aiding the operations of nature, by removing that very ob- 

 struction to the process of diffusing this " excess" of air. And here I would 

 just hint at a chemical error under which the reviewer labours ; inasmuch as 

 the "great excess of air" he speaks of, as being necessary to a " mixture of 

 the combustible and incombustible gases, in accomplishing the indispensable 

 condition of combustion — the proximity of the atoms to be combined," is a 

 very serious impediment, rather than a necessary aid, to that very condition. 

 For this well-established chemcial fact, fas my opinions are too " insane" to 

 merit attention,) I beg to direct the reviewer to Davy's "Researches on Flame." 

 And may I not here be allowed to remark, in a spirit of good humour, 

 that if I be that " ponderous gentleman" whose " attendants should insanify 

 with a few grains of common sense," other persons may possibly consider my 

 would-be guide as that imponderous and light-headed reviewer, whom it 

 would be well to ballast with a few grains of chemical knowledge, to qualify 

 him for steering his own bark, before he imdertakes to correct the reckon- 

 ings of others. But, badinage apart, this very " excess of air," which is here 

 laid down as " necessary," is as great an enemy to proper diffusion and per- 

 fect combustion, as a deficiency would be ; hut on this, it is unnecessary here 

 to dwell. To correct this impracticability of apportioning the admission of 

 air to the " ever-changing quantity of smoke evolved from an ordinary 

 furnace," I separate the air into two supplies, thus rendering them more 

 manageable, and, what is more important, less liable to interfere with and 

 mar each other's objects; a system, also, which has this practical value — the 

 causing them to he, to a great extent, mutual correctors of each other's defects. 

 The one supply is sent to the ash pit and bars, for the combustion of the 

 solid carbonaceous portion of the fuel; the other to the gaseous matter 

 evolved from it. 



Cut I ask, why shall this want of a more correct means of regulating the 

 supply of air to the demand, be so peculiat'iy chargeable on my mode of 

 admission ; while the ordinary plan of furnaces is so lamentably and wholly 

 deficient on this head — nay, even absolutely prohibitive of any attempt at 

 regulation ? My mode, to a great extent, practically corrects the evil (as I 

 am now showing in my papers on this subject in the Mechanic's Magazine), 

 while, by the' ordinary method, the supply of air is most restricted by the 

 body of fresh fuel on the bars, at the very time when an increased quantity 



is most required, by reason of the increased quantity of gas evolved. The 

 absence, then, of the means for " adjusting the quantity of influent air to the 

 variable condition of the fire," bears with intinitely greater force against the 

 old plan, so pertinaciously adhered to, and which rejects any effort towards 

 adjustment. Again; although this variable supply of air required has reference 

 to the gaseous matter evolved above the fuel, rather than to the solid matter 

 on the bars, yet these sticklers for a regulating valve would absolutely compel 

 the supply of air which is intended for such gaseous matter to pass through 

 such bars and body of incandescent fuel, where it necessarily loses much of 

 its oxygen, if not the whole; thus virtually sending the smallest quantity of 

 oxygen to the gases when they were most redundant. Let those, then, who 

 cavil for a regulating valve, first apply the argument to their own old favourite 

 system before they object to mine, which practically and to a great extent 

 meets the difficulty. 



The reviewer next observes — " But the. parturient mountain lias again 

 brought forth a mouse. This learned philosopher, after vapouring about atoms 

 and gases, presents us with — what ? a veritable antique smoke-burning fur- 

 nace." If this be true, then we must be prepared to call the .\rgand burner 

 a veritable smoke-burning lamp. This sneer at " vapouring about atoms and 

 gases" I must say is, at least, inappropriate from that pen which had just 

 before truly and scientifically urged the " indispensable condition of combus- 

 tion — the proximity of the atoms to be combined" — the veiy point on which 

 the whole atomic theory, as regards the union of gases, rests its value. 

 Again ; I am told " the sole peculiarity" of my plan is that " the air enters 

 by a greater number of holes than usual." Will the reviewer inform your 

 readers whether this peculiarity be not the very one which characterizes the 

 Argand burner ? Again ; " whether, of two smoke-burning projects, the least 

 objectionable is that which admits the air at one hole, or that which admits 

 the air at many holes, it would here be irrelevant to inquire." Now, Sir, that 

 is the real point worth inquiring into ; and this blinking the main question at 

 issue will not go down with your scientific readers, unless he can first per- 

 suade them that there is no difference between the briUiant smokeless burners 

 in our shops in Regent-street, and those flaring smoking flames which the 

 butchers' stalls exhibit ; the sole difference being that which is here said to 

 be irrelevant — namely, the difference between the one large bole and the 

 many small holes. For, chemically, the eft'ect is the same, whether the air 

 be admitted in jets to the gas, or the gas in jets to the air — my mode of ad- 

 mission being, in the words of Professor Brande, " an experiment upon the 

 large and practical scale which I have often made on a small and theoretical 

 scale, in illustration of the inaccuracy of the common terms • condsustible,' 

 and ' supporter of combustion,' as ordinarily applied." 



"We are informed, "says the reviewer, "that Mr. Bourne has a patent for 

 the same thiiig of the date 1838." I beg to say the reviewer is misinformed. 

 Mr. Bourne's patent is for the generation of gas from retorts placed in a fur- 

 nace over the incandescent fuel on the bars, and, when the gases are expelled 

 from these retorts, drawing the solid coke from them on to the bars below, 

 to keep up the body of incandescent matter. It must, therefore, be to this 

 invention that Dr. Lardner and Mr. Farcy's reports apply. But it matters 

 not; for if this identical "same thing" be so good under Mr. Bourne's name, 

 it cannot be so very insane under mine. On the merits of the actual invention 

 of Mr. Bourne, I forbear to speak ; of the actual plan of a furnace which he 

 afterwards adopted in the steamers on the Thames, after having rejected his 

 own, I have already said enough in my treatise, where I have given it in proof 

 of one of the erroneous modes of eft'ecting the combustion of the gaseous 

 products of coal : neither will I say anytliing of Mr. Bourne's anonymous 

 essay, now before me, out of respect to Mr. Bourne himself. 



But perhaps the gravamen of the charges against my presumption in ques- 

 tioning the practice of our " operative engineers," may be discovered by the 

 concluding observation, that " engineers and boiler-makers know their business 

 much too well to lack information from a pack of effervescent chemists and 

 druggists" — meaning the first chemical authorities of the day. Professor 

 Brande, Dr. Ure, Dr. Kane, Professor DanicU, <ic. I beg leave to assure the 

 reviewer that many of the first engineers and boiler-makers have, in a manner 

 worthy this inquiring age, expressed tliemselves in a very different manner, 

 urging me to pursue the inquiry, and follow up those experiments on the 

 large scale which have so opened tlicir eyes to the defective system and 

 empirical rules, on which they have hitherto relied. 



I am. Sir, 



Yours, &e. 



Liverpool, March 1 j. C. Vi'. Willums. 



