1819.1 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL, 



287 



Britannia Bridge. — At the meeting of the Chester and Holyhead Railway 

 Company, held on the 9th ult., Mr. Robert Stephenson made the following 

 report; — " The masonry of this contract is completed as far as practicable, 

 prior to the floating of the tubes ; awaiting that operation, the progress of 

 the remainder will depend upon the lifting. In this latter proceeding there 

 has been some delay, owing to an unsoundness in one of the large castings 

 of the new hydraulic press in the Anglesea Tower, which occasioned so 

 much leakage, as threatened at one time to render a new casting necessary, 

 which would have delayed for several weeks the process of lifting the tube, 

 which has been, as you are aware, floated into its position for being raised. 

 I have, however, the satisfaction of reporting that the leakage has been suc- 

 cessfully stopped, and that the operation of lifting is progressing, and might 

 by this time have been completed ; but I have deemed it prudent to lift by 

 short stages only, and to build up step by step underneath with brickwork, 

 in order ett'ectually to guard against the serious consequences which might 

 aiise from any failure or derangement of the hydraulic presses, whilst the 

 tube was suspended from them. Such an accident 1 believe to be very im- 

 probable ; but, after the fracture that took place in one of the cross-heads 

 during the lifting of the Conway tubes (which was fortunately discovered in 

 time to prevent a very serious disaster), I do not feel that I should be justi- 

 fied in omitting in the case of the Britannia tube (where a mishap would, in 

 all probability, interfere permanently with the navigation of the Straits) any 

 one expedient which caution can suggest. With these feelings, therefore, I 

 have, with your sanction, resolved to follow the course alluded to, notwith- 

 standing it will protract the time of lifting in each tube a fortnight or three 

 weeks beyond the period originally contemplated. The arrangements for 

 floating the next tube (which, with that already being lifted, will enable us 

 to complete one line of rails across the straits) are in a very forward state, 

 and will certainly be ready by the 24th inst,, with a view of taking advan- 

 tage of the spring tides of the 7th and 10th of September, if it should be 

 deemed expedient to do so. Upon this point I am hardly able to decide 

 positively at this moment, for if any delay should take place from some un- 

 foreseen contingency, it may be advisable not to float the next tube until the 

 following spring tides. No great loss of time would ultimately arise out of 

 this postponement, as the interval would be occupied in removing the presses 

 from their present positions into those for lifting the second tube ; and some 

 advantage would be gained by lessening the time during which the principal 

 channel for navigation would be interfered with. On the other hand, I think 

 it very desirable not to allow the season to advance further than absolutely 

 necessary before the next floating takes place. This latter consideratiou ap- 

 pears to me so important that we shall not fail to avail ourselves of the 

 spring tides from the 7th to the 10th of September, if consistent with the 

 further consideration of the circumstances 1 have mentioned as atfecting the 

 question. The present arrangements will, I believe, admit of one line of 

 railway being completed in the course of November. This conclusion is 

 arrived at from the results of our recent experience, and cannot far mislead ; 

 but I am bound to add, that the operations are so dependent upon casualties 

 which man cannot control, that the most careful calculations as to time may 

 not be exactly verified. I do not, however, see any reasonable grounds for 

 doubting that one line will be finished throughout by the abovemcutioned 

 date, or, at the latest, before the end of the year." 



Accident at the Britannia Bridge. — The raising of the monster tube of 

 this stupendous bridge to its final resting place is delayed for a month or six 

 weeks, in consequence of the lower part of the cylinder of the huge hy- 

 drauhc press on the Anglesea side bursting, on the 17th ult., with a tremen- 

 dous explosion, and in its descent on to the tube, a height of about 81 feet, 

 fell with a terrific crash. The press was at work at the time, and had raised 

 the tube about 3 feet during the lift this day ; and had it uot been for the 

 urgent and very precautionary means adopted, by packing and bricking under 

 with cement as the tube was being raised, the most dreadful consequences 

 were inevitable. One of the workmen was precipitated from a rope ladder 

 running from the top of the tube to the recess in which the hydraulic ma- 

 chine was fixed ; he was struck by the huge mass of iron in its ilesceut, and 

 now lies in a dreadfully crushed state. This most disastrous affair is to be 

 attributed entirely to a defective casting of the cylinder, and the raising of 

 the tube will, consequently, be delayed some time until the completion and 

 fixing of the new one in its place. The tube is now raised about 21 feet 

 above the water. 



High Level Bridge at Newcastle. — The high level bridge over the Tyne at 

 Newcastle was opened for the passage of trains on the 2'2nd ult., the morn- 

 ing mail train south being the first that passed. There is only one line of 

 the permanent rails laid, hut the other is in a forward state, the carriage- 

 way is also just approaching completion, and in a few months it is expected 

 the entire structure will be made available for public use. The general 

 character of both mason and metal work of this magnificent structure is of 

 the most solid and substantial kind. The masonwork was let by contract to 

 Messrs. Rush and Lawton, the firm having been extensive contractors on 

 various lines where the works had required strength and solidity in the 

 masonwork, despatch in the execution, and a careful superintendence. Tliese 

 requisites have not been neglected with regard to this noble structure. The 

 contract for the metal and iron work was let to Messrs. Hawks, Crawshay, 

 and Co., in which they were assisted by the firms of Messrs. Losh, Wilson, 

 and Bell, and J. Abbott and Co. The bridge consists of six arches, each 

 having a span of 125 feet, with two curved approaches of about 69 feet in 

 length, formed of cast-iron pillars and bearers, from the design of Mr. R. 



Stephenson. Messrs. Losh and Co. executed the castings for the approaches, 

 and Messrs. Abbott and Co. the arches. The stipulated price was about 

 120,000^. The arches are circular and made of cast-iron, the whole weight 

 of which is above 6,000 tons. The railway is carried over the backs of the 

 arches in the usual manner; and below this is formed, by suspension, a car- 

 riage and foot road for the convenience of vehicles and foot passengers. 

 This portion of the bridge, however, will not be completed in less than 

 another month, the workmen being busily engaged in laying down the wood 

 pavement. 



Pesth Suspension Bridge. — The Mining Journal observes : " This splendid 

 bridge is generally supposed to have been completely demolished during the 

 recent events of the war operations between the Hungarians and Austriaris ; 

 but, up to the present time, w^are glad to learn, from a correspondent on 

 the spot, no serious damage has oeen done to the structure. In the first re- 

 treat the Austrian army was obliged to make from Peslh, the general gave 

 orders for the destruction of the bridge, and 60 cwt. of powder were placed 

 on it, 30 cwt. on each side, or under the chains, with the view of breaking 

 them. Both charges were fired at the same time; the person who superin- 

 tended the arrangements and fired the charges, was literally dashed in pieces. 

 The eflfect it produced on the bridge was the breaking down of the road, 

 which consists of transverse cast-iron bearers, to a considerable extent. The 

 vibration of the chains was. very great, and continued for some length of 

 time ; but after the retreat of the Austrians the bridge was again repaired. 

 The Hungarians, however, were obliged again to retreat over the bridge, 

 when Derabinski gave orders for its destruction. Mr. Clark, at Pesth, weni 

 to Dcmhinski, and remonstrated with him, and told him that it would be 

 nothing to his credit, as a general, to destroy so fine a structure. The ge- 

 neral told Mr. Clark that his orders were peremptory, but after a great deal 

 of negociation, he consented that some of the bearers should be taken down, 

 and put into boats, and taken down to the Island of Schutt, the boats to be 

 scuttled, and sunk in deep water ; this was done. Then came the Russian 

 and Austrian armies, when the bearers were taken up, and the bridge again 

 repaired." 



Lighthouse. Lamps and Reflectors. — Avery interesting experimental trial 

 of the powers of several lighthouse reflectors took place on the evening of 

 Friday the 17th ult., at Woolwich, under the direction of the Trinity House, 

 and, we believe, at the request of the Boanl of Admiralty. The lamps and 

 reflectors tried were those in ordinary use by the Trinity House, and two 

 others on plans of the invention of Mr. A. Gordon. The Trinity House 

 lights, manufactured by Messrs. Wilkins, of Long Acre, are used in nearly 

 all the lighthouses of the kingdom ; the reflector is parabolic in form, and 

 the one tried was 22 inches in diameter, and 9 inches in depth ; the lamp of 

 tlie Argand construction, at 3} focal distance. One of Mr. Gordon's appa- 

 ratus consisted of a reflector of the hyperbola form, 22 inches in depth, and 

 19 in diameter, with Argand lamp at IJ focal distance; and the other of 

 Mr. Gordon's lights has, in addition, four annular glass refractors. The 

 lamps were lighted at half-past eight, on the upper story of the Royal 

 Marine Barracks, and the power of the lights directed to the village of 

 Rainhara, in Essex, a distance of about 6J miles, at which place, the gentle- 

 men to whom was confided the task of reporting on the efficiency of the 

 respective apparatus, were assembled. It a|)peared to be the almost unani- 

 mous opinion of the witnesses of the experiments that the Trinity House 

 light was the best on the whole: for although Mr. Gordon's lem apparatus 

 was certaitdy equal to the other when seen in a direct line, it was inferior 

 when tried at an angle of 7 degrees of divergence from the line of observation ; 

 and that, without the lens, was not equal in any point of view to the ordinary 

 reflectors. The cost, also, we are informed, would be in favour of the para- 

 bolic reflector. 



Lighthouse, Cape Pine, Newfoundland. — There was lately exhibited at the 

 premises of Messrs. De Ville, and Co., 367 Strand, the lantern and lighting 

 apparatus for the lighthouse about to be constructed at Cape Pine, in New- 

 foundland. The dense fogs and sudden changes of temperature to which 

 that coast i.« liable, make it a matter of great importance, not only that such 

 a work should he erected, but that it should be of the most eflScient charac- 

 ter. Accordingly, the present apparatus has been prepared by the authority 

 of the Admiralty, under the direction of Mr. Alexander Gordon, whose 

 talent in this respect has already been thoroughly established by the light- 

 houses erected by him at Jamaica, Bermuda, Point de Galle, Ceylon, and 

 elsewhere. In the present lanterns, Mr. Gordon has introduced an important 

 alteration— viz., that of making the reflector more concave, securing thereby 

 a more powerful light. The tower is to be of cast-iron, and, with everything 

 connected with it, has been constructed in this country. Although the order 

 for the work was not given till the 23rd of April last, the whole will be ex- 

 hibited, 320 feet above the sea, on the headland of Cape Pine, during the 

 autumn. This despatch is the more extraordinary, considering the diflBculty 

 of access to the site of the lighthouse, there being neither road nor harbour, 

 and the surrounding district being uninhabited except by a few wreckers. 

 Mr. Gordon has united with the revolving light of the tower a new and in- 

 geniously constructed screaming apparatus, the invention of, and patented 

 by .Mr. George Wells, to act as a fog signal, instead of by guns, bells, and 

 gongs, which have hitherto been used for that purpose, but the sound of 

 which too nearly resembles that of the waves on a stormy coast to render 

 them really serviceable. 



The Northern Artesian Well, near Southampton, has now been bored to 

 353 feet in depth. The progress has been impeded by a stone 22 inches 

 thick, and the supply of water has decreased through decay of the rods. 



