202 



THE CIVIL l-XGIXEER AND ARCHITECT'S JOURNAL. 



[June, 



kiiKl appear to have been taken, and the endeavour to force a circidation in 

 the state the pipes were then in, produced the disastrous event that ensued. 

 It is not the object of the patentee to throw l)lame upon others, he only 

 wislies to show that his apparatus may be used with perfect safety, if the 

 same care and attention be bestowed upon it, as is required by every other 

 mode of warming. 



There are some palpable errors in the report of .Messrs. Davies and Ryder 

 in their remarks upon the inequality of the Iicat given out by the pipes in the 

 Natural History Museum, and the manner in wliicb they attempt to account 

 for it. They observe, that the heat in those pipes had been repeatedly stated 

 to l)Ccome the greatest at places remote from the furnace, and that the fact 

 was confimed by their own observations and subsequent experiments ; and in 

 another part of the Report they account for it by stating, that the minute 

 bubbles of steam which rise rapidly to the upper ]iart of the flow-pipe become 

 there condensed into water again. From this acknowledged fact they deduce 

 the inference that, •' as condensed steam wherever it occurs produces about 

 seven times as much heat as the same quantity of water at the same tem- 

 perature, we h.ive at once a reason for tlie heat of the pipe being generally 

 greater at a distance from the furnace than contiguous to it." This is a mani- 

 fest absurdity, for it is impossible that increase of beat can be produced by 

 the condensation or cooling of steam. There cannot, therefore, be the slightest 

 doubt that the statement of those gentlemen, that the heat is generally greater 

 at points distant from the furnace than contiguous to it, is founded altogether 

 in misconception and error. Another observation from which erroneous con- 

 clusions are drawn is, that the temperature of the pipes is influenced by the 

 variation of their internal diameter, this is not the case; the amount of heat 

 conducted ofl^ depends upon the surface exposed to the atmosphere, and not 

 upon the internal diameter. Equal surfaces exposed to the atmosphere give 

 off equal heat, whatever variation there may be in the velocity of the current 

 of the water within the tubes. 



The objection No. 1, relative to the possibility of an explosion from the 

 inadequacy of the expansion tube, has been already met in the description of 

 the apparatus in the former part of this paper ; and overfilling the apparatus 

 is impossible while the filling-pipe is made the only medium of supplying it, 

 and the serew-plug of the expansion tube is at tlie time of tilling taken off. 



In objection No. 2, it is inferred that, because a pint of water may be con- 

 verted into steam capable of exerting a powerful mechanical force, and pre- 

 sent a pressure upon the tubes " sufhcient to ensure their destruction," that 

 such must inevitably be the case. Ten years' experience has, however, proved 

 the contrary ; any quantity of steam w hich can be formed in an apparatus 

 properly put up, the tubes are perfectly able to resist. 



Objection No. 3 supposes the presence of hydrogen gas in the apparatus 

 to be a common occurrence, instead of a very rare one ; and where it has 

 occurred it has invariably arisen either from a faulty construction of the ap- 

 paratus, or great neglect in its management. Admitting, however, that hy- 

 drogen gas has been formed witliin the ]>ipes, no explosion can be produced 

 by its expansion, as its expansive power is far less than that of water; neither 

 can it explode within the pipes by ignition, as it requires an admixture of 

 atmospheric air to render it explosive. 



The remaining objection urged against the use of the apparatus is, the dan- 

 ger of explosion from stoppage in the pipes. This is a very unusual occur- 

 rence, and rarely happens except in seasons of very severe frost, when it may 

 always be prevented Ijy keejjing a slumbering fire. Tlie addition of three 

 per cent, of salt to the water will also prevent it from freezing, even during 

 such severe weather as was experienced last winter. The objection of stop- 

 pages by extraneous substances getting into the pipes, is scarcely worth no- 

 tice ; the last operation of the workmen in erecting a new apparatus is always 

 to scour the pipes well through by means of a forcing pump, and then to 

 close thera up. How then can any substances get into pipes thus closed in 

 every part, except by design .' 



It seems that previously to putting up the apparatus at Mr. Walker's, those 

 at the Natural History Museum, and Messrs. Vernon and Company's, had 

 been tried and found " unsatisfactory :" that is to say, they could not be 

 sufficiently overheated. The patentee can show Messrs. Davies and Ryder 

 some hundreds of apparatuses that woidd prove still more " nnsatisfuctory " 

 to them than those just named. Since the foregoing remarks were written, 

 Mr. Perkins has received a letter from Sir Robert Smirke, in which that gen- 

 tleman says, " I am sorry to know that you think the partial use of my 

 answers to tlie questions sent to me from Manchester (as printed in the Re- 

 port there) has been in any degree prejudicial. If it has been so, I think 

 you ought in the reply you are about to publish, to counteract that effect, 

 especially as it was one not at all intended. They should, at least, have 

 directed equal attention to my remark tliat complete seciu'ity, under every 

 contingency, might be obtained from the adoption of your safety-valves." 



Comment upon this is unnecessary ; it only strengthens the feeling which 

 the perusal of Messrs. Davies and Ryder's Report has very generally produced, 

 viz. that it is very unjust, and that the absurd experiments detailed in it were 

 conducted with any view rather than that of candid investigation. 



If those who possess the means of obtaining the information would make 

 known the causes of all the fires that have come under their cognizance with- 

 in the last eight or ten years, as far as they can be ascertained, the patentee 

 is confident that such a statement would speak more in favour of his appara- 

 tus than the most laboured arguments. There are not wanting, however, 

 many persons even in Manchester itself, who, placing more confidence in 

 their own knowledge of the apparatus, foundetl on several years' experience, 



than in the Report, have unhesitatingly expressed their determination to con- 

 tinue the use of it as heretofore. 



The safety-valves, alluded to by Sir Robert Smirke, have been but recently 

 applied ; and cfl'ectually provide for any casualty which can arise from a 

 stoppage in the jiipes. 



In conclusion, the Patentee begs that the Directors of Assurance Companies, 

 and the public gcner.illy, will not hastily form their opinion of Perkins' hot- 

 water apparatus from tlie very erroneous reports which liave been circulated 

 respecting it, as it is his intention to request a committee of competent gen- 

 tlemen connected with insurance offices to inspect an apparatiK properly con- 

 structed, and which he wishes to have subjected to any test to which such 

 committee may think proper to submit it. 



G, Francis Street, Regent Square, 

 .■IprilWth, 1841. 



LOCOMOTIVE ENGINES IN A.MERICA. 



AVe have received a copy of the -Annual Report of the Canal Commissioners 

 of Pennsylvania. Among the documents thereto appended, is the report of 

 the superintendent of motive power on the Philadelphia and Columbia rail- 

 road, in which an engine built by Mr. Ross Winans, of this city, is spoken of 

 in the most flattering terms, which applies not only to the particular engine, 

 but to the class of engines built by Mr. Winans. We extract the following 

 from the report : — " In addition to the difl'erent engines of the ordinary con- 

 struction purchased by the undersigned, is one built by Ross \Vinans, of Bal- 

 timore, which, as well as others, was contracted for by a resolution of the 

 Board, previous to the date of my last report. The general principle upou 

 which this engine is constructed is similar to the one which, by the order of 

 ray predecessor, had been placed on the road near a year before my appoint- 

 ment. It is, however, entirely different in its proportions. 



" This engine was constructed by special orders, as an experiment in the 

 use of anthracite coal as a fuel to generate steam ; and, on trial, has met all 

 my anticipations. It is very large and heavy, with more than double the 

 power of any other machine on the road. It burns anthracite coal exclusively, 

 and from the additional space of fire-box, obtained by its increased size, has 

 advantages in the use of that article, which is not, and which cannot be pos- 

 sessed by any other plan of engine. It is intended exclusively for the 

 transportation of heavy trains of burthen cars. It will haul double the ordi- 

 nary train, Imt owing to its great weight, must he run very slowly over the 

 road." 



We have understood that this engine rests its entire weight on/o!(r/)ro- 

 pelliiKj wheels, each wheel supporting about the same weight as each one of 

 the two propelliny wheels of the largest class six wheel engines on the Phila- 

 delphia and Columbia road. Tl>e engine last built by Mr. Winans, and which 

 we have before noticed, is still more powerful than the one spoken of in the 

 report ; but having overcome the difficulty that has heretofore been deemed 

 insurmountable, of placing eight wheels under his engine, and couuecting the 

 motive power with all of them, so as to get the adhesion of the entire weight, 

 without having a weight on any one wheel which is oppressive to the road. 

 The engine now furnished weighs 19'33 tons, when in running condition, and 

 is mounted on eight propelling wheels, which divide the weight equally 

 among them, ])utting 2-42 on each wheel. The passenger engines of Norris' 

 construction, in such extensive use, weigh about 10 tons when in running 

 condition ; but as they have only two propelling wheels, the greatest adhe- 

 sion which they can render available, is that resulting from G'TO tons resting 

 on the driving wheels, which is but little more than one-third the adliesion 

 obtained !)y Mr. Winans' eight wheel engine, while the weight on eacli driv- 

 ing wheel of the Norris is 3-35 tons, nearly a ton more than the weight on 

 each wheel of the eight wheel engine. The power of every locomotive en- 

 gine is limited by the greatest adhesion of its wheels on the rails ; the .idhe- 

 sion is directly as the weight resting on the propelling wheels collectively. 

 The greater the weight bearing on any one wheel the more destructive to the 

 road. The greatest economy in transportation results from the use of the 

 most powerful engines that can be employed consistent with the strength and 

 character of the road on which they are to run ; hence the advantage of in- 

 creasing the number of propelling wheels. 



An account was published a few days since, in a Philadelphia paper, of a 

 gross load of 481V tons being drawn over the Philadelphia and Reading Rail- 

 road, by an engine built by Messrs. Baldwin, Vail and Ihifty, the weight of 

 wliich is stated to be 11'92 tons, and the weight on the drinng wheels 6-30 

 tons. .\s this is less than one-third the weight on the driving wheels of Mr. 

 Winans' eight wheel engine, which has been shown to work to the full extent 

 of its adhesion, it follows that it woidd be capable of taking over the Read- 

 ing road three times the amount of the load above-named. — Baltimore 

 Clipper. 



Till' Railway Guard's Uliistle.—Vfon one of the London and Birmingham 

 trains an apparatus is fitted up, consisting of rods attached to every carriage, 

 and under the control of the guard, communicating witli a whistle on the 

 engine, called the " guard's whistle," quite distinct from the one sounded 

 by the driver, and used only to give warning to him, to increase or decrease 

 his speed, to stop, ^c, according to signals previously a ranged and under- 

 ood. — Yorksltire Gazette. 



