31S 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



fOlTOBIJl, 



The liritnnnia and Conway liriilses. — The report of Mr. Stephenson, 

 presented to the niet'tinR of the Chester and Holyhead Itailway, on the 

 21th ult., slated tlial the coostructiun of the second tube of the Couway- 

 bridge is far advanced, and there is no doubt it will be ready for removal 

 by the middle of October. The pontoons have been strengthened, the cap- 

 stans re-erected, and every other arrangement in a forward state for its 

 erection. About three-fourths of the masonry of the Britannia-bridge have 

 been coniplf-ted ; and, taking the progress now making as a guide, it is cal- 

 culated that the first tube will be ready for lifting to its place in the course 

 of next March or April. The iron-work at the Britaunia-brid;;e has pro- 

 gressed even more rapidly than was expected, and the four large tubes are 

 just approaching completion. The whole of the central portion of the tubes 

 is finished, and the castings at the ends are now being inserted. The 

 scafl'olding for the end tubes on the Anglesea side is complete, and a large 

 proportion of the iron is already punched for their immediate commence- 

 inent. The scaffolding necessary for the tubes on the Carnarvon side will 

 be erected immediately, to open the line throughout as rapidly as possible, 

 livery arrangement is being made for floating the tubes as soon as the 

 masonry is ready. The works throughout the whole of the line are stand- 

 ing in the most satisfactory manner. The daily passage of heavy trains 

 through the Conway lube for four months, together with a series of care- 

 ful observalions as to the efl'ects produced, have completely established the 

 correctness of the views upon which the designs for this and the Britannia 

 were based. The cost of these structures has very much exceeded what 

 was originally calculated upon ; on re-considering, however, the whole 

 subject, Mr. Stephenson is satisfied that the method which has been 

 adopted is certainly the most eligible, if not the only practicable one. 



Mode of Extinyuishing Fires at Sea. — The following letter has Ijeen ad- 

 dressed by Dr. Reid to a daily morning paper : — " As the danger from fire 

 at sea is attended with so many appalling circumstances (of which we have 

 had a recent instance in the melancholy catastrophe of the Ocean Monarch), 

 I beg to submit for the public consideration, and especially underwriters, the 

 following plan, as a clieap, simple, and eflicient method of preventing the 

 occurrence of such accidents. Flame or combustion cannot go on where 

 there is carbonic acid gas. This is one of the elementary principles of ehe- 

 mistry. It may he shown in various ways. A lighted taper plunged into a 

 jar of carbonic acid gas is instantaneously extinguished ; or, if we take the 

 glass of a common argand burner, and close the upper end of it by a flat 

 plate of glass, or even by a piece of card or pasteboard, firmly, so com- 

 pletely as to prevent any current of air through the tube, on introducing for 

 about an inch or so the flame of a candle at the other extremity (the glass 

 of the argand burner being held upright) it will, usually in the space of little 

 more than a minute, he extinguished, merely by the accumulation of the 

 carbonic acid gas produced by its own combustion. The production of 

 carbonic acid gas is completely at our command, for on adding dilute sul- 

 phuric acid to chalk, we can set at liberty, in the space of two or three 

 minutes, enormous volumes of this so-called fixeil air. The cost of material 

 for a ship of 1,000 tons would not exceed 15/. or 201. sterling By means 

 of tubes proceeding from the upper deck in connection with a cistern 

 containing the dilute sulphuric acid, to the quarters below where there is 

 most likelihood of danger from fire, or moveable hose (made of gutta 

 percha), which can be introduced into arjy part of the vessel — the oil of 

 vitriol, previously diluted with water, can be at once poured over the chalk 

 (which is to be thrown down in the place where the fire rages), and imme- 

 diately, the carbonic acid being set at liberty, the fire is extinguished ; for 

 combustion cannot go on in an atmosphere of carbonic acid gas. I have 

 been much occupied experimenting on this subject, and find that from five 

 tons of chalk, as much carbonic acid gas may be obtained as will be sufli- 

 cient to completely fill a vessel of 1,000 tons burden. The expense of laying 

 the tubes will not exceed 30/. or 41)/. ; and, once laid, there is no further 

 trouble or expense. I may observe also (but experiments are at variance on 

 this subject) that it is not requisite to have an atmosphere absolutely consist- 

 ing of carbonic acid gas to extinguish flame, for some experiments show 

 that a taper does not burn in an atmosphere of three parts atmospheric air 

 and one part carbonic acid gas. Lightning-conductors are provided for ships 

 — surgeons also to take care of the health of the crew — assuredly no ex- 

 pense (and it is but a trifle) would be grudged to secure a ship and its pas- 

 sengers from the contingency of such a melancholy mishap as that of fire. 

 If this method will do — and there seems to he everything in its favour — all 

 our emigrant ships, indeed every ship, ought to be secured against a calamity 

 which really must be held as the most dreadful that can occur to a vessel at 

 sea." 



iSouth- Eastern Ruilway. — The works at London Bridge for enlarging 

 the station and widening the Greenwich Hallway viaduct, suspended 

 during the monetary panic of 1847, have biien resumed. The bridge to 

 cross Bermoudsey-slreet is rapidly progressing. 'I'he Craveseud branch is 

 also in a very forward state. It is expected lo be opened for public traflic 

 eirly in the spring. 



Railway Siyunts. — Another of the many contrivances suggested for en- 

 abling passengers in railway trains to communicate with the engine-driver 

 or guard, has been recently patented, though it differs little from several 

 others of the same kind. The patentee is Mr. Richard Baird, of Dundee, 

 and be claims the application of tubes to railway carriages, and the com- 

 bination of cords, wires, or chains with the tubes, in such manner that 

 either the passengers or guard may sound the stcam-whistle. It is proposed 

 to connect the cords passing tbrou(;h the tubes under each carriage by 

 spring hooks. 



Great Western Docks. Plijmnulli. — These d^icks are being proceeded 

 with rapidly, and, when completed according lo the design, will furnish 

 accommodation superior to that aliorded by any docks of similar extent. 

 The inner basin, or floating dock, will be capable of cuolaining and aO'urd- 

 ing ample wharfage for 12 steamers of the largest size, a number, we 

 believe, equal to that accommodated by the great basin at I'ortsmoutb, 

 recently opened. There will be two entrances to this basin ; one will 

 adniii merchantmen of the largest size, and steainbuals of ojdiiiary dimen- 

 sions, for two or three hours before and after high waier — through the other 

 the largest screw- steamer can pass at high water. The area of the outer 

 basin will be nearly 30 acres. If this basin should be deepened to the ex- 

 tent proposed, vessels can enter and be afli'at in it at all times of the tide 

 without Ihe delay of pasing through a lock. This is an advantage not 

 possessed by Liverpool, and many oilier ports. The entire extent of wharf- 

 age will exceed a mile, and the area of ground for stores is adequate to 

 the greatest possible trade. — Devonporl Chronicle, 



Birkcniieud Docks — It appears by the Lirerpool Times, that the most 

 active preparations are going on in the engineer's department of these 

 works, in the preparation of working drawings, &c., for the recommence- 

 ment of the construction of the docks forthwith. Arrangements, it is said, 

 have been made for raising the requisite capital, and no doubt remains as to 

 the successful accomplishment of theobject of the new trust. An important 

 trade is opening up in the exportation of coal from the Welsh mines, 

 which can be brought, it is said, to Birkenhead docks, and put on board 

 vessels at very considerably less cost, and with far greater facility, than 

 from the Lancashire coal-field. 



The Grimsby Docks, — These are mighty works, and are proceeding 

 with most satisfactory rapidity, alike creditable to all concerned. The 

 chief engineer, Mr. Uendell, is expected shortly ; but the engineer, Mr. 

 Adam Smith, who is very properly called the resident engineer, is always 

 on the works. Tliere is a defect, or rather a sinking, in one portion of Ihe 

 piles from the " blow sands'' — a uame upon which tradition has exhausted 

 its ingenuity, and has summed up all by ascribing to demoniac agency the 

 " fathomless pit." Shakspeare was right in putting into U<imlet's solilo- 

 quising thoughts, " Oh, what a mighty piece of work is man !" and had 

 he lived to see the mighty pieces of work which man achieves, some other 

 as appropriate exclamation would by him have been furnished. One 

 hundred and fifty acres taken from the sea, and defences raised to prevent 

 the mighty ocean claiming back 'its own," and such defences as will 

 resist its foaming rage, let its battering waves lash it as they may — bor- 

 rowing from some of its sister land chalk as the means of defence, of 

 which no less a quantity than 10,01)0 tons are every week ctmveyed on a 

 road of iron. By October, it is expected all will be ready to receive bis 

 Royal Highness Prince Albert, to lay llie first stone of the intended Royal 

 Albert Grimsby Docks ; and, withiu tliiee years, a dock of 37 acres will 

 be ready to receive vessels laden witii foreign stores. So much progress 

 could not have been made but for the perseverance of Mr. Adam Smith, 

 and those under his directions. — Notlivghamshire .Journal. 



Clifton Suspension Bridge. — Upw-irds of i'40,U00 have already beea 

 expended upon this underlaking, and no more money being furtnconiiag 

 the works are now at a stand-still. 



Improvements in Bridge Building. — \ fine wooden bridge has recently 

 been erected by the Cambuslang-road trustees, across the river near 

 Dalmarnock, lo supply the place of the old one, which is now 30 years 

 old, and very much decayed. The new bridge was commenced only live 

 mouths ago, and was built from a design by Mr. Robson, C.E. The whole 

 length of the briilge is 355 feet, and the width withiu the side-rails is 

 28 feet. There is a footpath on each side, covered with asplialte pave- 

 ment, and the road-way is composed of a. mixture of asplialte aud whm- 

 stone metal, broken, 7 inches deep, and laid on the lop of the planking, 

 which had been previously well caulked with oakiini, and coaled with 

 pitch and sand, for the purpose of making it water-tight. 



Circular Sawing. — An experiment has been lately made at the S.iw-mills, 

 Woolwich-dockyard, with the view of testing the efljciency of circular saws 

 in cutting through the centre of rough timber of a diameter nearly equal to 

 that of the saw itself. An elm tree — one end of which was of the full 

 diameter of the saw— was placed upon one of the circular sawing machines, 

 having a saw 4 feet diameter, and a self-feeding motion, in the usual way. 

 By this motion the tree n as brought towards the saw, and passed over it ; 

 and by a reverse motion, it was turned back. The cut made in the tree, 

 passing over the saw, was in dead wood all the way, and fully 20 inches 

 deep. After the tree was run back, it was turned over, and adjusted for a 

 second cut, to line with the first ; and in this position it was brought for- 

 ward, as before, and completely divided in two. 



Method of Welding Iron, Steel, and Sheet-Iron. — la an earthern vessel 

 melt borax, and add to it one-tenth of sal-ammoniac. When these ingre- 

 dients are properly fused and mixed, pour them out upon an iron plate, and 

 let them cool. There is thus obtained a glassy matter, to wliich is to fje 

 added an equal quantity of quicklime. The iron and steel which are to be 

 soldered, are first heated to redness, then this compound, first reduced to 

 powder, is laid upon them ; the composition melts and runs like sealing- 

 wax. The pieces are then replaced in the fire, taking care to heat them at 

 a temperature far below that usually employed in welding ; they are then 

 withdrawn and hammered, and the surfaces will he found to be tlius per. 

 fectly united. The author asserts that this process, which may be applied to 

 v\elding sheet-iron tubes, never fails. — Mechanics' Magazine. 



