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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[November, 



ELFXTRO-MAGNETIC RAILWAY LOCOMOTIVE. 



A trial of lliis very ingenious machine, constructed by Mr. Daviilson, was 

 made last montli on 'the Blinliur-li and Gla.'gow Railway, in [iresence of a 

 miniher of genllemen. mariy of whom were eminent for ihoir scientific knov- 

 lerige. The cunslriiction of ihe carriage is the first atlemrt which has been 

 made in Ih's country to apply the powers of electro-magnetism to railway 

 Iraflic, and from Ihe success which attended this trial, sanguine hopes may 

 be entertained that lh« period is not distant when it will eitlur supersede, in 

 many cases, the employment of steam, or lend a powerful aid to tliis mighty 

 instrument in all the operations in which it is at pre.-ent employe. I. Tlie 

 carriage was impelled along the railway about a mile and a half, and travelled 

 at Ihe rate of U|)Hards of four niiUsan hour, a rate whicb might be increased 

 by tiving greater power to the batteries, and enlarging the diameter of the 

 wheels. We understand that the carriage was built :.t the e.\pense of the 

 Railway Company, ami we cannot but congratulate them in having the dis- 

 cernment to emjiloy Mr. Davidson, a gentleman of mucli priactica! knowledge 

 and talent, to whose genius great discoveries have been made in electro- 

 magnetism, by whom the carriage was projected, and to whose unwearied 

 exprlions the practicability of the sclieme isalmost placed beyond a doubt. 



The dimensions of the carriage are IG fee^Kg by 7 feel wide, and is pro- 

 pelled by 8 powerful electro-magnets. Tl^tarriage is supported by lour 

 wheels of 3 feet diameter. On each of ihe two axles tbere is a wooden cylin- 

 der, on which are fastened three bars of iron at equal distances from each 

 other, and extending from cnil to end (jf the cylinder. On e.ach side of the 

 cylinder, and resting on the carriage, (there arc two powerful electro-magnets 

 When Ihe first bar on the cylinder has passed tli(|.faces of two of these mag- 

 nets, the current of galvanism is then let on to the other two magnets. They 

 immediately pull the second bar until it comes opposite Ihem. The current 

 is then cut otf'from tliese two magnets, and is let on to the other two. Again 

 they pull the third bar until it comes opposite, and so on — the current of 

 galvanism being always cut ofl from the one pair of magnets when it is let 

 on to the other. 



The manner in whicli the current is cut off and let on is simply Ihus ■ — At 

 each end of the axles there is a small wooden cylinder, one-half of which is 

 covered by a hoop of copper ; the oth^r is divided alternately with copper 

 and wood (three parts of wood and three of copper). One end of the coil of 

 wire which surrounds the four electro-magnets, presses on one of these 

 i-ylinders, on the part w hich is divided with copper and wood ; the other end 

 of the coil presies on the other cylinder in the same manner. One end of the 

 wires or conductors which comes from the battery, presses constantly on the 

 undivided part of Ihe copper on each cylinder. When one of Ihe inn bars on 

 the wooden cylinder has passed Ihe faces of two magnets, the current of gal- 

 vanism is let on to the other two magnets, by one end of the coil « hich sur- 

 rounds the m.ngnets, passing from the wood to the copper, and ihereby form- 

 ing a connexion with the battery. This wire continues to press on the cop- 

 per until the iron bar has come opposite the faces of the two magnets, which 

 were thus charged with magnetism. On its coming into that position, the 

 current is cut off from these two magnets, by the wire or rod of copper pass- 

 ing from Ihe copper to the wood, and ihereby breaking Ihe connexion willi 

 the baltery. But when the wire or rod of copper leaves the copper on the 

 one cylinder, it leaves the wood, and passes to the copper on the other cylin- 

 der at the other end of the axle, and in so doing connecis the other two 

 magnets with the baltery, ami they pull the next iron bar in the same man- 

 ner. At tlic oilier end of the carriage there are otiier four magnets and 

 Kooden cylinder, with iron bars arranged in ihe same manner. 



The battery which is used tor propelling the machine is composed of iron 

 and zinc plates immersed in dilute sulj Iiuric acid, tlie iron plates being fluted 

 so as to expose greater surface in the same space. The weight propelled was 

 about six Ions. — EdiubiiraJi Ecmiina Jcunml. 



.IMPROVEMKNT IN SlilP BUILDING FOR .STEAM NAVIGATION. 



A most ingenious model has fallen under our observation, of which Captain 

 Drew (the destroyer of the piratical Caroline) is ihe inventor, /or strength- 

 ening ships of war, so as to make il all but impossible they shall become 

 hogged. To steam-vessels of the larger class Ihe adoption of this simple 

 and comparatively inexpensive machinery will prove of most vital impor- 

 tance. The immense weight of the engines requ'site for a steam-ship render 

 her more than ordinarily liable to break amirlsliips. C'a(itain Drew's plan 

 was, we are told, suggested by the ingenious and admirably effective opera- 

 tion lately performed on the Penelope. 



The grand feature of his project is to relieve a steam-vessel from the vast 

 weight of machinery amidships, and to throw it upon two distant parts of 

 the ship, n,uch more capable of sustaining it ; and if there be any one vessel 

 to which such an adjunct will be more especially necessary than another, it 

 is Ihe Penelope, whose maeliinery will be placed exactly in the space occupied 

 by the 60 ft. of timber which remains to be added to its length. Captain 

 Drew's plan consists of two longitudinal pieces of limber firmly trussed to- 

 gether, constiucteil on something like the principle of llie arch of a bridge, 

 which will be capable of bearing an immense weight. These bearers are to 

 be covered by a platform for the machinery of four-inch plank ; so that tlie 

 strongest part of the vessel will, in future, be that which has hitherto proved 

 the weakest. It is well known that Ihe unlbrtunate President was broken- 

 backed before she loft the British Ch inr.el on her last trip, irom the immense 

 weight of her machinery amidships — ;lie undoubted cause of her melancholy 

 catastroj he. The owners of the British Queen are, we are told, about to cut 

 her intotwo, for ihe purposeofavoiiling a similar catastrophe. And it is well 

 known that ihe loni; steam-vessels running in Canada seldom last more than 

 5 or (i years, from the same cause. If, Iherefnre, Captain Drew's plan should 

 realiiie the expectations we have formeil of it, it cannot fail of proving of 

 most vital iinijurtance lo Ihe navy at large, and to steam ships in particular. 

 VVc h.ad almost forgotten to notice another important advantase that will 



be gained by Captain Drew's plan. The circumstance of the machinery 

 being placed upon a iilalform that will be, to a certain extent, ekislic, will 

 obviate in a great degree that constant jar which is so trying to the timbers 

 of a steam-ship, and so inconvenient to iis occupants. 



We have tiie greatest pleasure in speaking of this invention .as we think it 

 deserves, inasmuch as we have understood that Captain Drciv has no inter- 

 ested motives in [dacing it before the public, lie seeks no patent, and de- 

 sires no reward beyond the credit of being instrumental in preserving not 

 only valuable properly, but human life, from destruction.— - t.'/ij(erf Sen-ice 

 Gaze/te. 



STEAM NAVIGATION. 



The Itiunch of the *' Prince Albert " Iron Steitm Ship took place on Friilay, 

 the 30th ."'ept., at Mr. Coutts's yard, at Newcastle. The following are her 

 proportions; — Length between per]iendiculars l."« ft., length over all 180 

 ft., main breadth 19 ft. 6 in., depth of hold 9 ft.^G in., draught of water 

 when light with machinery 3 ft. 6 in., and when loaded with passengers 

 4 ft. 6 in. The ribs or frames of this vessel are formed of angle iron, 4 in. 

 broad on the web, placed 2 ft. apart, and Ihe tliickness of her plates are 

 three-eights, five-sixteenths, and one-fourth in. respectively. She lias four 

 longitudinal kelsons 14 in. deep, \ in. tliick, with 8 cross kelsons of the same 

 size of plate ; the whole of these kelsons have strong angle iron fixe 1 on 

 their upper edge and riveted lo the ribs and plates of the vessel, thus forming 

 tlie bottom into a level platform of great strength, on which the engines anj 

 boilers are placed. There are other parts of the Prince Albert novel in their 

 construction, such as the iron deck beams and gunwdiale stringer, the former 

 is formed of plate J in. thick and 8 or 9 in. deep, with a piece of angle iron 

 on each side to which the deck deals are attached by screw bolts; these 

 beams form a diagonal knee at the sides of the vessel, and are attached to 

 every alternate rib, forming one of Ihe strongest and lightest beams yet con- 

 structed. 'Ihe iron gunwale stringer is formed of plate J in. thick, and from 

 9 to 11 in. broad, wilh a flange turned downwards, and covering the plates of 

 the vessel to which it is riveted, and another flange on its inner edge, tur.ieJ 

 upwards and let into the waterway or covering board ; this stringer is fixej 

 down to the ribs and beams of the boat, and will form one continuous hori- 

 zontal knee from stem lo stern. The covering board is of pitch pine, 3 in. 

 thick and 14 in. broad, bolted down to the gunwale stringer, and forming 

 wilh it a very strong protection from accidents or damage by collision with 

 vessels or otherwise. The deck deals are only 4 in. wide, and are tongued 

 w ith iron hoop let in, with white lead in the grooves so as to preclude th« 

 necessity of caulking or pitching the joints. There are two iron (vater-tight 

 bulk-heads, forming the vessel into three distinct compartments. The lines or 

 model of the boat are considered by judges to be laid down on the most 

 scientific principles ; and altogether she forms one of the finest specimens of 

 scientific skill and mechanical arrangement of marine architecture that we 

 have witnessed. And should her machinery prove equally complete and effi- 

 cient, which, from the m.anner Mr. Coutts speaks of it, we believe will be the 

 case, tlie Prince Albert will be one of the fastest boats yet started on the 

 Thames. The Prince Albert will be towed to London to receive the engines 

 which are made liy the owners, Messrs. Brailhwaile, Milner & Co. The 

 boilers are of Spider's patent tubular, somewhat like locomotive boilers, with 

 this dillerence, that the water circulates through the tubes instead of the 

 fire. They were made and put on board Ihe boat here by Mr. Coutts, and 

 are said to be capable of generating sufficient steam for 130 lo 140 h. p. in a 

 space of about 7 ft. in the length of ilie vessel.— .Vt'!«cas(/c Paper. 



Naval Experiments on Ihe Defences of Steam Boilers. — A highly interesting 

 experiment was tried at Portsmouth last month, on board the Excellent gun- 

 nery-ship. Captain Sir Thom.as Hastings, to test the efficacy of the defences 

 of the boilers in steam-ships of war. One of the greatest difficulties lo sur- 

 mount in order to render the steam navy of greater efficiency in action, is 

 to afford adequate protection to the boilers ag.iinst the shot of the tnemy, 

 as a ball perforating Ihem would at once pla;e the vessel hors de combat. 

 With Ihe view of aHording this protection to the boilers, several war steamers 

 have been fitted up with extra defences at the parts where the boilers are 

 fixed. 'These defences consist of 15 plates or layers of metal, e.ich ^ inch 

 thick. The object of the experiment on board the Excellent was to ascertain 

 « bat resistance these defences of boilers would offer to a cannonade at point 

 blank distance, which is 400 yards. An iron target was prepared, made ex- 

 actly of the material wdiich constitutes the protection of ihe hoilers of a 

 steamer, and placed at the distance of 400 yards from the slii|i, from which 

 guns at difleient calibre were fired at it. Admirals Sir E Codrington and 

 Parker, and a great number of naval ollicers, including those from the Aus- 

 trian irigate, were present to witness the experiment. The first shot that was 

 fired was an eight-inch hollow shot, and was projected from a ti8-pouniler, 

 medium gun. It s'ruck the bull's-eye, or centre of the target, and, slightly 

 indenting it to the depth of about ,') in., rebounded therefrom, and was split 

 into several pieces by the concussion. The second shot was a solid 32- 

 pounder, and was fired from a gun of 9 ft. 6 in. ; it struck the edge of the 

 target, glanced oil', and was split into two pieces. The third shot hit the 

 centre of the target, where it lodged, having peneir ited several plates. The 

 fourth shot struck Ihe third, and sent it clean through all parts of the iron, 

 splitting it into numberless pieces, which were found on the off-side of the 

 V, ooilen stage on which the target was fixed. The fifth and .sixth shots went 

 through the perforation made by the third and fourth. About 10 oilier shots 

 were fired, all striking the target in various parts, and completely destroying 

 it. The residt of this experiment has shown how totally inadequate are the 

 present defences of the boilers of war ster.mers to protect them from the as- 

 savilts of the enemy where a precision of fire had been atlained. — Times. 



Sale of the Great Western Steam Sliip.—On Monday afternoon, the Utli 

 October, at two o'clock, the steam ship Great Western was oflcred for saU 



