128 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[March, 



Stevenson & Sons, of Edinburgh, consists of two arches of 75 ft. span each, 

 with a versed sine of 11 ft. 6 in., the centre pier being 32 ft. 1 in. long and 

 10 ft. in breadtli, making the distance between the faces of the abutments 

 160 ft.; it was constructed of soft red sandstone, and the abutments were 

 built up solid, the greater part of the masonry being ashlar ; the total cost 

 of the bridge was stated to be £6058. 



An account of the building of IJ'ellington Bridge, over the river Aire, at 

 Leeds, by Mr. J. Temperley, was also read. This bridge was executed from 

 the designs of the late Mr. Rennie about 20 years since ; it crosses the river 

 where it is 100 ft. wide and 6 ft. deep ; it consists of a segmental arch of 

 100 ft. span, with a versed sine of 15 ft., constructed of stone from the 

 quarries of Bramley Fall, which are about four miles from the bridge ; the 

 abutments are built in radiating courses, external faces, which are horizontal, 

 the whole being well bonded together : the total quantity of masonry is 

 80,000 cubic feet. The method of forming the foundations, as well as of 

 the coffer-dams, and centre was given in detail, and it was stated that the 

 total cost of the bridge was only £7250. 



Mr. G. Rennie made some clear and consise remarks on the ancient arches, 

 of which traces have been discovered, by the recent researches of travellers ; 

 alluding to Perring's account of ancient arches discovered at Thebes, the 

 bricks of which bore the name of Sesostris, which would carry back the 

 knowledge of the arch to a period of upwards of 3000 vears. He noticed 

 also the size of the stone lintel among the Greeks — the etruscan arches 

 found in Italy, and also the more modern but very bold arches still remaining 

 in Italy, Portugal and Spain. 



A paper by Mr. F. Nash was then read describing a new kind of girder, 

 composed of a number of diagonal bars of wrought iron abutting against 

 each other, with cast iron transoms ; these latter supporting the pressure 

 and the former the tension. This mode of construction has been recently 

 introduced in France; and the paper after describing a number of prelimi- 

 nary experiments on small girders, gave the details of the proofs, to which 

 four girders placed side by side with a bearing of 74 ft. 8 in. had been sub- 

 jected, by order of Mons. Teste, the Minister of Public Works, Paris. From 

 this it appeared, that with a load of 62 tons, the deflexion in the centre was 

 l^W in., and that the girders resumed their original position on the weight 

 being removed, after bearing it for a month. In order to test the effect of a 

 sudden shock, a cart loaded with 4^ tons of iron was caused to break down 

 suddenly in the centre of the bridge, without producing any prejudicial effect 

 beyond crushing the flooring planks. The weight of these four girders was 

 stated to be 20} tons. 



March 12. — The President in the Chair. 



The discussion upon the knowledge of the properties of the arch pos- 

 sessed by the ancients was renewed, on the presentation by Mr. Page of 

 drawings of two arches standing near some Cyclopean remains at Cape Crio, 

 (Cnidus). There was no positive evidence of the date of these arches, but 

 from their being built without mortar, and the massiveness of their con- 

 struction, it was agreed that they were probably of the same period as the 

 Cyclopaean work among which they were situated. 



The failure of the Pont de Boverie, at Liege, which sunk so much and 

 cracked on the piers to such an extent as to oblige it to be taken down, was 

 fully explained by Mr. Rennie, who presented a drawing of it. Mr. B. Green 

 also exhibited a design for the proposed stone bridge of eight circular arches 

 for connecting Gateshead with Newcastle-upon-Tyne, at a high level. He 

 also exhibited some beautiful specimens of ornamental bricks, made by 

 Mr. Barnes, of Newcastle. 



The first paper read was an " Account of the harbour of Pidteney Town," 

 (Wick, Caithness, N. B.) This harbour, which was designed by Mr. Telford 

 for the British Fisheries Society in 1803, and for which the first part of the 

 works was executed between 1805 and 1811, by Mr. Burn, at an expense of 

 £16,400. The success of the herring fishery, and the consequent increase 

 of the shipping frequenting the port, rendered a more extensive harbour essen- 

 tial, and in 1823, other plans, which received the approval of Mr. Telford, 

 were carried into effect by Mr. Bremner. The various extensions of the 

 works were given in great detail, with the ingenious methods employed in 

 their execution, as also the account of the devastation caused by the sudden 

 inroad of the sea upon the unfinished work of the pier, when 100 ft. in 

 length of the pier head was swept away in one tide, besides doing much 

 damage to the other parts of the works. The ruined works were secured 

 for the remainder of that year by binding them together with chain cables, 

 and in the succeeding summer the works were completed, and have stood 

 so ever since. Some interesting observations were made as to the relative 

 action of the waves upon long and short slopes of the sea faces of piers, 

 and the author's experience evidently leads him to prefer a slope of about 

 one to one for works which are exposed to a heavy sea. 



The various ingenious methods adopted by tlie author for conquering the 

 difliculties before him, excited great interest, which was kept up by the next 

 paper, also by Mr. Bremner ; it was a " Description of casks nsed in floating 

 large stones for building sea walls in deep water." These casks, which were 

 *?^°"K'y built of fir staves, hooped externally with irou, and supported in- 

 side by radiating bars, like the spokes of a wheel, were used instead of crane 

 barges, for conveying stones of 30 to 40 tons weight, for securing the foot 



of the sea walls of Banff Harbour, which had failed. Two of these casks, 

 of 445 ft. cube each, were nsed to convey stones of 30 tons weight, by pass- 

 ing the two chain cables, which were wound round them, through the eyes 

 of the leweses which were fixed in the stone at low water, at which time the 

 chains being hauled down tight, when the tide flowed, the buoyancy of the 

 casks floated the stones, and they were towed by a boat over the place where 

 the stone was to be deposited — the lashing being cut away, the casks were 

 let go, and the stone fell into its seat. This method was found to succeed 

 perfectly in weather that would have destroyed any craue barges, and the 

 works of Banff Harbour were thus secured from further degradation, and 

 were subsequently entirely restored at a comparatively small cost. The 

 drawings and enlarged diagrams gave fully the details of this method of 

 working. 



A model of Farani's railway switch was exhibited, and its self-acting 

 motion, in guiding the carriages into the sidings or on the main lines, as 

 required, was shown by the inventor. These switches were stated to have 

 been used on the Grand Junction Railway for Gome considerable time. 



March 19. — The President in the Chair. 



In the recapitulation of the conversation of the meeting of March 12th, 

 there were read some interesting remarks by Colonel Leafe, on the know- 

 ledge possessed by the Greeks of the properties of the arch : he contended 

 that numerous examples still existed of their having used it, but from the 

 solidity of their constructions, the nature of the materials they employed, 

 and the architectural character of the edifices, which were chiefly temples, 

 the arch was evidently less employed than among the Romans, who used 

 different and less solid materials. 



A description was then read " of the formation of the Town-lands of 

 Mnsselburgit, on the Firth of Forth," by Mr. James Hay. This was a cu- 

 rious instance of an extensive tract of nearly 400 acres of land, being 

 formed by an alluvial deposit, in about 300 years. The river Esk, when 

 swollen by rain, is stated to bring down quantities of the detritus from the 

 hills, which, with the soil washed from the banks of the low lands, is ar- 

 rested when it meets the tide, and is thrown upon the beach ; this, being 

 mingled with large boulder stones, become fixed ; the sand is blown over it 

 by the heavy north winds, to which the shore is exposed, and thus this large 

 tract has been formed. The diagrams showed the several lines of high 

 water at various dates, and that nearly the entire town is built upon land 

 thus recovered from the sea without the aid of art. 



The next paper read was " a description of an hydraulic traversing frame 

 at the Bristol terminus of the Great Western Railway, by Mr. A. J. Dodson, 

 Assoc. Inst. C.E. The action of this machine, the object of which is to 

 transport the railway carriages from the arrival side of the terminus, to the 

 departure side, or to any one of several intermediate lines, was thus de- 

 icrilied : an opening being made in the train, the apparatus is pushed on to 

 the line of rails, and the carriage required to be moved, is run over it when 

 the frame is quite down, it being then sufficiently low to allow the carriages 

 to pass freely over. As soon as the carriage is brought directly over the 

 apparatus, a man works a pump, acting upon four hydraulic presses, which 

 raise the frame until both sides are in contact with the axles of the carriage 

 wheels, and raise the flanges of the wheel clear of the rails ; the whole ap- 

 paratus, with the carriage suspended upon it, is then easily transported to 

 any of the lines of rails, when, by unscrewing a stopper, which allows the 

 water to flow back from the presses into its cistern, the carriage is lowered 

 on to the rails, and the apparatus is rolled over ready for re-commencing the 

 operation, the whole transit not having occupied more than one minute and 

 a half. The action of the apparatus (which was made by Mr. Napier, York 

 Road) was stated to be very satisfactory, and its cost to have been about 

 .f220. 



An account was then read of the Landslip in the Ashley cutting on the 

 Great Western Railway, by Mr. J. G. Thomson, Grad. Inst. C.E. The 

 cutting, wliich was described, is situated about five miles on the London 

 side of Bath ; it was made through a mass of detritus from the neighbouring 

 highlands, consisting of sand, oolitic gravel, vegetable matter, and stones of 

 the great oolite, lying upon the blue lias clay and marl. The whole district 

 was extraordinarily full of water, and appeared to have defied all attempts 

 to drain it ; this accumulation of water softened the clay, turning portions 

 into soft silt, and when, by cutting away a portion of the foot, which was 

 situated on a slope, tlie su|)port was taken away, the whole mass was set in 

 motion, and every attempt to resist it was fruitless. The details of the at- 

 tempts at driving water headings, sinking pits, which collapsed and were 

 obliged to be filled up with stones and fagots, and all the other engineering 

 devices that were adopted, were given with great minuteness, and when 

 being aided by some well executed drawings, gave an interesting account of 

 a good specimen of one of the difficulties to be encountered by the railway 

 engineer, in the ordinary course of his labours. 



The paper was an example of that which has been so frequently insisted 

 upou at the meetings of the Institution, namely, the advantage to the civil 

 engineer of a knowledge of geology, by which his progress would he safely 

 made under such circumstances. 



