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THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[M 



AY, 



milted average pressure was 7 lbs. ; in the second period 14 lbs. ; and 

 in the last period IS lbs. 



Wc cannot oonchiile this better than by laying before our readers 

 the elocjuent \ indication of Western steam navigation, which was 

 given before Congress by the Hon. Mr. Rumsey, of Kentucky. 



" Sir, yoii have no aritlimctic of powers vast enough, hy wliiili to estimate 

 the henctits of the steam boat iii a pecuniary point of view alone, its 

 labours, too, have tendeil, in no small dcgreo, lo //le preseri-a/ion of /inmnn 

 life. I am aware that the truth of the last assertion may not be luiivcrsally 

 admitted ; but it will scarcely be questioned, at least by a western or soutli- 

 wcstern man. who recollects the old mode of conducting our commerce. 

 Small as the commerce was before the introduction of the steam boat, it drew 

 ofl' a larger jjortion of the poi)ulation than is now necessary to transact it, 

 although so immensely extended. Even then, more <lied in the long, and 

 evposed, and laborious voyages in keels and barges, or the exhausting return 

 by land, under a vertical sun, than now perish by steam boat explosions. But 

 the) (Iropi)cd ort' one by ouc ; they sank obscurely into the grave by the way- 

 side ; or, after re:iehing their homes, fell victims to disease incui'red by a so- 

 journ and travel in southern climes. The consumption of life, though known 

 to be great in the aggregate, happening so much in detad, made no public 

 impression. But now, every steam boat itecident creates a sensation, and is 

 proclaimed in the universal press of the country. If the mighty commerce 

 now in progress on the western waters, bad to be conducted in the old way, 

 it would require the agency of so many individuals, that it would not belong 

 before the sides of the public roads from New Orleans to the Upper States, 

 and the banks of the great river which pours into the gulf the congregated 

 waters of nearly half a continent, would be almost continued grave-yards." 



NOTES OF THE MONTH. 



This month has been more feitile in deaths than in any thing else. In 

 this number is Thomas Drumniond, Lieutenant in the Royal Engineers, F.R.S., 

 Under Secretary of State for Ireland, Ike. His labours in the Ordnance Sur- 

 vey of Ireland, and his discovery of the hydro-oxygen light, which bears 

 his name, are well known to the public. As an Irish Railway Comndssioner 

 it was our lot to oppose him, but we are free to confess that it was to Urum- 

 niond that the rejiort was indebted for its most valuable portions. He died 

 on the 18th ult., at Dublin, and was honoured with a public funeral, which 

 he highly merited. 



I'itts, the sculptor, unfortunately conuuitled suicide on the 16tb nit., in bis 

 oOtb year. He was an artist of high merit, who it is to be hoped will receive 

 that honour now which he pined for in his lifetime. Among his works are 

 the Shield of Eneas, from Virgil, and that of Hercules, from Ilesiod, com- 

 positions and designs from Virgil and Ossian, intended to be published in the 

 same form as Flaxman's from Homer, the Nuptials of Perithous, the Ajjo- 

 theosis of the EngUsb poets, and several other reliefs which adorn Bucking- 

 bam Palace. The Brunswick Shield was another of bis works. — The Cheva- 

 lier Gasse is also dead. He was architect to the King of Naples, Corres- 

 ponding Memljcr of the French Institute, and of the Institute of British 

 Architects. 



The Easter holidays have given some check to business, so that we have 

 little to record. Spencer's Electrotype is now receiving the attention which 

 it deserves ; some months ago it was smothered under the blaze of photo- 

 graphy. Seals and cojiies of medals are made by this means with great 

 accuracy and celerity. — Jacobi's galvanic engraving is also acquiring ])nblicity. 

 We may mention by the bye that as his other electric inventions have not 

 exceeded those of our countrymen, so bis application of electro magnetism .as 

 a motive power is deriveil from an Englishman. — Sniee's battery described in 

 our present number will give fresli power to the professors of this important 

 branch of science. — Claudet and Houghton's specimens of Dagnerre's process 

 of photography now exhibiting in Holliorn, are well worthy of inspection, 

 they give good earnest of the aid this admirable invention will artbrd to the 

 arts. Its appbcation to the debneation of architectural and antiquarian sub- 

 jects will make it of great value to the profession. The Elgin marbles should 

 be copied by this method. 



The vacuum engine is the wonder next to be exhibited ; a new apiilication 

 of agriculture, by which it is said,above twenty square nules can be cultivated 

 by one stationary engine has been patented, and will be shown to the puldic 

 on a small scale early in the ensuing month. — It will be recollectccl that 

 Hague's draining apparatus is on this ]dan, and a steam engine erecteil by 

 Mr. Hague at Constantino]de, works a powder mill seven miles off, at a place 

 where the (Irani! Signer refused to allow any steam engine to be erected 

 within that distance. — Mr. Maugham, the lecturer on chemistry, has re- 

 moved from the Adelaide Gallery to the Poletecbnic. At this hitter Institu- 

 tion an ingenious application of propellers to the balloon is shown, although 

 their success on a large scale is doubtful, from their incapacity to contend 

 with currents of air. 



The plan for embankment of the Thames is now before the legislature, so 

 that we may ex|icct sumethiug .is a beginning. — The wood pavement com- 

 panies are getting on faster than the asphalte, they are at work .at Ibieking- 

 hara Palace, in the Strand, Oxford Street, St. Giles's, and Lamli's Conduit 

 Street The elasticity of this material forms one of its best properties. Under 

 most of these jiavements a firm bed of concrete nuxed with Koman cement 

 and puzaolauo U laid, rather expensive we should tliiuk, 



The Marine Gallery at Hampton Court Palace was opened on Easter .Mon- 

 day, 80 that the maritime nation has at last two marine galleries.— The (io- 

 verument School of Design at Somerset House has made another .step out of 

 the humdrum system ; having obtained a set of casts from .Messrs. Lofts in 

 Dean-street, llow they could persevere in their exclusion of the figure, it is 

 difficult to conceive ; they have only to go into their own schools and look 

 at the drawings of the same ornaments affixed to the walls; those from casts 

 are full of life and spirit, and in high relief, those from engravings more laboured 

 are dead and fiat. In fact the wisest thing they could do would be to turn 

 every engraving out of the school, where tbey can substitute nature or casts, 

 and above all never to let a boy begin to draw frotu a drawing, — set him before 

 the Apollo or the Venus at once. This has been tried at the Leicester-square 

 school with full success, even on its very young boys. The latter is far before 

 Somerset House in principle ; thanks to their badly remunerated Director 

 .\Ir. De Moucbet. The modelling class at Leicester-square gets on well. We 

 hojie the inspection of Mr. Wyse at Somerset House last month will do some 

 good ; that patron of the arts has, it is said, suggested many modifications in 

 the establishment. One fruit of bis visit is a report from the council, the 

 first since their institution. Pretty fair from a national establishiiient ! It 

 is a pity these establishments are not more frequented, where the working 

 classes can obtain first rate instruction in the arts for xivjience a weok. The 

 whole number of students at the school is not more than two hundred. 



pNEi'.MATic Experiment o.v thi. Birmingh.vm, Bristol, .\nd Thamks 

 Junction Railwav. — The engine-house is built, and the communicating 

 tube between it and the raUway, by which the exhaustion of the main tube is 

 to be effected, is nearly laid. The permanent way and rails are also almost 

 completed, and fit for the laying down of the tubes for a considerable distance 

 out of the 1 j miles on which the experiment is to be made. We perceive also 

 that a great many of these tuues arc already arrived and on the gi'ound. Tbey 

 are nine inches diameter, and are lined inside, to about the tenth of an inch 

 thick, with a hard unctuous sid)stance, much resembling, in its disagreeable 

 and sufibeating smeU, hard tallow. The slit or aperture of the tubes through 

 which the arm communicates with the rumiing piston and the carriages is 

 about !„ inch. \\"c understand, if the experiment be successful, the company 

 are to liave the use of the patent gratis, for devoting the road to the trial, anil 

 are to purchase the whole apparatus and pre])arations at cost price ; and if it 

 docs not succeed, all is to be cleared otf within a given time. Supposing the 

 experiment etfects all that its advocates expect, we cannot see the use of so 

 small an ajijiaratus in such a place. If we remendier right, the inclination of 

 the road, about that part, is 120 feet a mile; therefore, the traction is more 

 than three times that on a level, or above 2t lbs. to the ton. But a circular 

 tube 9 inches diameter, fully exhausted, and exclusive of all friction, would 

 only draw about 031 fts., or, at 24 lbs. per ton, under 40 tons. The probabi- 

 lity, however, is, that it will never in that length be half exhausted; so that 

 the absolute load it would take would be under 20 tons, carriages, load and 

 all, assuming a perfect absence of all friction in the machinery. AVe sliall, 

 however, be much surprised, if the useful efl'ect is anything like this. Our 

 opinion is, that the patentees have made the ajqiaratus much too sm.all for any 

 useful i)urpose upon such a road, and also for the purpose of showing otf the 

 invention well, assuming it to be all that can he expected of it. A few days 

 ago the works were suspended, in consequence of a dispute between the 

 Alessrs. Sanmda and the contractors, about the point of delivery of the tubes 

 — that is, whether it should be a few yards on the noi-tb, or a few on the 

 south of the crossing of the Great Western line. Where so much is involved 

 as here, tins dispute is equally as ridiculous as that of the Lilliputians and 

 their neighbours, about which cud eggs ought to lie broken. — Uaihoay 

 McKjazuie. 



Galvanic Engrax'ing.^U is not generally known that the method of 

 producing fae-similies of engraved plates by means of voltaic electricity, as 

 indicated by Mr. Brande, Mr. Faraday, and Professor Jacobi, has been fre- 

 quently demonstrated with complete success by Bachboffnor, of the Polytec- 

 nic Institution, in Regent-street, at which estaldishmeut many satisfactory 

 specimens may be witnessed. The process is as follows : — The plate from 

 which the duplicate is to be taken is first placed in a vessel properly adapted 

 for the jHupose, and is then covered with a solution of sulphate of copper, 

 through which the galvanic stream is transmitted. This causes a decomposi- 

 tion, or, in other words, the constituents of the salt arc removed from each 

 other, the metallic copper resulting from the action being deposited in a series 

 of thin laToina" upon the original plate. This deposited copper forms a second 

 plate, which, on removal from the other, exhibits every line a?ul mark traced 

 by the graver or etching-tool upon it, with this difierence, that wdi.at is bas- 

 relief in one is alto-relief in the other, and the engraved lines of the original 

 are raised lines in the duplicate. The sheet of copper thus iirodnced becomes 

 a normal plate or mould; from wduch, by a similar process, an acl injiiiituiu 

 number of plates may be taken, in even- respect equal to the original, and 

 callable, like it, of giving perfect printed impressions. The value of this 

 practical discovery is great, inasnuieb as it will supersede the necessity of 

 expensive steel-plate engr.ivings, by nuilliplying copies of those on copper 

 plates at the cost of a few shillings and loss of a few days only. Impressions 

 from medals, coins, and dies may be obtained in the same way, of which 

 there are several specimens in the gallery of the Polytecnic Institution, as 

 well as a very large duplicate copper plate of an elaborate engraving from one 

 of Domeuiehing's pictiues. 



