60 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[FsBRUARTj 



Ecdaiastical Archtecture. Decorated Windows. Edited witli de- 

 scriptions, by Edmund Sharpe, M.A., Arcliitecl. London; Van 

 Voorst. Part I. 



Tliis is one of tlie works we announced some time ago as forthcom- 

 ing from Mr. Van Voorst's library, and calculated to be of some inte- 

 rest and utility. This opinion is not diminished by the appearance 

 of tlie first part, which contains eight authentic examples of windows 

 in the decorated style. The examples are well chosen, and have in- 

 terest in themselves, and tliey are brought out with the finish which 

 usually characterizes Mr. Van Voorst's works. We would, however, 

 particularly call attention to some points of considerable importance, 

 and which would greatly improve the series. We would suggest that 

 at the bottom of the drawings the contour or section should brt given 

 of the mouldings, and that in the drawings, the jointings of the stones 

 should be accurately marked. It is also desirable that the dimensions 

 of the parts should be given, and not merely the rough measurement, 

 of the opejiing of the windows. We do not perceive that Mr. Sharpe 

 has in any case given the age of the churches from which the ex- 

 amples are taken. 



A Thermometrical Table. By Alfred S. Taylor. London: Willats, 



1845. 



Mr. Taylor is lecturer on chemistry in Guy's Hospital, and he has 

 published a table with accompanying description, which by inspection, 

 gives the corresponding degrees of tlie scales of Fahrenheit and 

 Reaumur and the Centigrade scale, at the same time that it exhibits 

 a most copious list of the temperatures by which various substances 

 are affected. It is calculated to be highly useful, is very elaborate, 

 and from Mr. Taylor's high character, we have every reason to pre- 

 sume it is very accurate. 



Papers on Subjects connected with the Corps of Royal Engineers- 



Vol.7. London: Weale, 1845. 



This work prospers under its editor, Ca|)lain Denison, and the pre- 

 sent volume contains many valuable and practical papers, although it 

 is to be- observed that they are not for the most part on military works 

 or works executed by tiie Royal Engineers, but are descriptions of 

 civil engineering works, executed by civil engineers. We do not 

 complain of this as detracting from tl'.e work, or detracting from the 

 character of the Corps of Royal Engineers ; on the contrary, the num- 

 ber of valuable civil engineering papers greatly enhances tlie nature 

 of the Work, and it shows the deep interest tlie Royal Engineers take 

 in every branch of their profession. Through want of sp ice we defer 

 our remarks upon the papers until next month, 



A Treatise on the Steam Engine, by the ./Irtizan Club. Parts 1 to 7. 

 Longmans and Co. 



We purposely deferred offering any notice of this work until several 

 numbers had been published, as the early ones did not offer any 

 Dew materials connected with the steam engine. In fact, they may 

 almost be considered a reprint of Mr. Farey's work on the 

 steam engine, the greater part of the illustrations being identically the 

 same. To this we should not so much object, if the "Club" had 

 acknowledged the source whence they were taken, but this has been 

 most cautiously avoided ; neither does it do Messrs. Longmans much 

 credit for having sanctioned sucii a wholesale application of materials, 

 from another work without some kind of reference or acknowledgment. 

 It may be very true that Mr. Farey's work is Messrs. Longmans' 

 copyright, and it might be said they had a right to do what they 

 pleased with their own, but we deny the application of this when they 

 engage a professional gentleman of high character to write a work, 

 which he does not undertake entirely for the sake of the few 

 pounds he may obtain, but in which he has his reputation at stake 

 and hopes to increase his fame; on such a view we maintain it is 

 neither acting fairly towards Mr. Farey nor towards the public in thus 

 making, without acknowledgment, use of his materials and drawings. 

 With these preliminary observations we shall proceed to the consi- 

 deration of the later numbers. 



The three numbers last published are fully illustrated with wood- 

 cuts, showing boilers of every description ; many of these cuts appear 

 more like sketches than drawings laid down to scale. In fact, no 

 engineer could set out a boiler from most of them; they do not tell us 

 what is the thickness of the plate iron, how put together, how the tie 

 bolts are applied, in fact scarcely any details are shown. It may be 

 said, who wants such information ? We reply, most readers who may 

 have been tempted to purchase the book from the prospectus issued; 

 which tells us "A popular treatise is, by its very nature, unsuitable to 

 the uses of the operative engineer, as h necessarily excludes all re- i 



ference to those niceties of adjustment and minutiis of construction, the 

 due elucidation of which constitutes the chief value of a practical 

 treatise." There appear to be some remarks made on the bailers of 

 one of the leading engineers of the day, as if written in spleen, which 

 we consider perfectly uncalled for, as the boilers of that firm are well 

 known to have been generally most successful, and we believe have 

 opened the eyes of steam boat proprietors as to the wasteful expendi- 

 ture of some boilers made in the north. It would be offering a good 

 service to the public, if the "Club" will favour them with tlie 

 actual consumption of fuel per trip of the Tagus by the old boilers 

 and the new boilers. If we find the result in favour of the former we 

 shall th<'n be disposed to agree with their remarks ; but from what we 

 have heard we believe the result will be greatly in favour of the newr 

 boilers. 



Notwithstanding the observations we lave thought proper to make, 

 there is still a great deal of valuable information, and the numerous 

 examples of boilers that have been shown may direct the attention of 

 engineers to those that have been found good, and ascertain more 

 about them. They may also, by being brought together, prevent per- 

 sons from taking out patents for boilers which have been long in use. 



The last number, we observe, concludes the account of the varieties 

 of boilers, which is followed up by some excellent remarks on boilers, 

 from which we make the following extract. 



We have already stated that a cubic foot of water raised into steam is 

 reckoned tquivalent to a horse power, and that to generate the steam with 

 sufficient rapidity, an allowance of one square foot of tire bars, and one square 

 yard of effective heating surface, are very commonly made in practice, at 

 least in land engines. These proportions, hov/ever, greatly vary in different 

 cases ; and in some of the best marine engine boilers, where the area of fire- 

 grate is restricted l)y the breadth of the vessel, and the impossibilitj' of firing 

 long furnaces effectuafly at sea, half a square foot of fire-grate per horse power 

 is a very common proportion. Ten cubic feet of water in the boiler per 

 horse power, and ten cubic feet of steam room per horse power, have been 

 assigned as the average proportion of these elements ; hut the fact is, no 

 general rule can be formed upon the subject, for the proportions which 

 would be suitable for a wagon boiler would be inapplicable to a tubular 

 boiler, whether marine or locomotive; and good examples will in such cases 

 be found a safer guide tlian rules which must often give a false result. A 

 capacity of three cubic feet per iiorse power is a common enough proportion 

 of furnace-room, and it is a good plan to make the furnaces of a considerable 

 width, as they can then be fired more efl'ectually, and do not produce so much 

 smoke as if they are made narrow. As regards the question of draft, there 

 is a great difference of opinion among engineers upon the subject, some pre- 

 ferring a very slow draft and others a rapid one. It is obvious that the 

 question of draft is virtually that of the area of fire-grate, or of the quantity 

 of fuel consumed upon a given area of grate surface, and the weight of fuel 

 burned on a foot of fire-grate per hour varies in different cases in practice 

 from 3^ to 80 lbs. Upon the quickness of the draft again hinges the ques- 

 tion of the proper thickness of the stratum of incandescent fuel upon the 

 grate ; for if tlie draft he very strong, and the fire at the same time he thin, a 

 great deal of uncombincd oxygen will escape up through the fire, and a need- 

 less refrigeration of the contents of the flues will fie thereby occasioned ; 

 whereas, if the fire be thick, and the draft be sluggish, much of the useful 

 effect of the coal will be lost by the formation of carbonic oxide. The length 

 of the circuit made by the smoke varies in almost every boiler, and the same 

 may be said of the area of the flue in its cross section, through which the 

 smoke has to pass. As an average, about one-fifth of the area of fire-grate 

 for the area of the flue behind the bridge diminished to half that amount for 

 the area of the chimney has been given as a good proportion, but the exam- 

 pies which we have given, and the average flue area of the best of which we 

 shall furnish, may be taken as a safer guide than any such loose statements. 

 \¥lien the flue is too long, or its sectional area is insufficient, the draft he- 

 comes insutlicient to furnish the requisite quantity of steam ; whereas if the 

 flue he too short or too large in its area, a large quantity of the heat escapes 

 up the chimney, and a deposition of soot in the flues also takes place. This 

 last fault is one of material consequence in the case of tubular boilers con- 

 suming bituminous coal, though indeed the evil might be remedied by block- 

 ing some of the tubes up. The area of water-level we have already stated as 

 being usually about 5 feet per horse power in land boilers. In many cases, 

 however, it is much less ; but it is always desirable to make the area of the 

 water-level as large as possible, as wfien it is contracted not only is the water- 

 level subject to sudden and dangerous fluctuations, but water is almost sure 

 to be carried into the cylinder with the steam, in consequence of the violent 

 agitation of the water, caused by the ascent of a large volume of steam 

 tlirough a small superficies. It would be an improvement in boilers, we 

 think, to place over each furnace an inverted vessel immerged in the water, 

 which miglit catch the steam iu its ascent, and deliver it quietly by a pipe 

 rising above the water-level. The water-level would thus be preserved from 

 any inconvenient agitation, and the weight of water within the boiler would 

 be diminished at the same time that the original depth of water over tlie fur- 

 naces was preserved. It would also be an improvement to make the sides 

 of the furnaces of marine boilers sloping, as shown iu the sketch, instead of 

 vertical, as is the common practice, for the steam could then ascend freely at 

 tlie iustaut of its formation instead of being entangled among the rivets and 



