branch, leased to the Great Northern, has been recently (October) opened, and will be extended to Cambridge. The Coventry and Nuneaton branch, and a portion of the Rugby and Stamford branch, have been opened by the London and North Western Company. In the East Anglian district, the Eastern Union Company have completed their line from Ipswich to Norwich; while a few short branches have been opened in other directions. The Harwich branch, unfortunately for the interests of that town, is still unmade. In the metropolis many minor sources of traffic have become developed. The Euston Square terminus has been greatly enlarged, so as to be fitted for the accommodation of any amount of traffic that can reasonably be expected. A station is about to be formed at Kilburn, to accommodate a short or "omnibus" traffic, in connexion with the Birmingham and East and West India Dock Junction Railway' (it is a pity that the sponsors of railways are so verbose). This long title belongs to a railway from Camden Town to Stepney, about eight miles in length; it is connected at one end with the Birmingham, and at the other end with the Blackwall Railways, and is to be leased by the London and North Western Company. Part of it has lately (October) been opened, from Upper Islington to Stepney, with intermediate stations at Hackney and Bow; the same carriages run on the Blackwall line from Stepney to Fenchurch Street, and it therefore forms a new but circuitous route from the northern environs into the city. Trains run every quarter of an hour throughout the day; and the low charge of fourpence is fixed upon, for the whole distance of eight miles. There will be two other stations-in Camden Town near the Veterinary College, and in the Hampstead Road near Chalk Farm: possibly also another in the Caledonian Road. Besides this short passenger traffic, there will ultimately be a goods traffic from the great Camden station to the Docks and the Thames: indeed this was the primary object of the line. The Great Northern terminus, at King's Cross, is in progress; the Small Pox Hospital and the Fever Hospital having been pulled down, and new buildings erected for those establishments near Highgate and near Holloway, respectively. The Blackwall Railway terminus, at Fenchurch Street, will shortly be a more busy spot than at any former period; for in addition to the arrangement with the Camden branch, the Essex and Norfolk traffic is (to some extent) brought on the line by means of the Bow branch, which connects the Blackwall with the Eastern Counties railways. The North Woolwich branch of the last-named railway is likely to lead both to extensive building speculations, and to the formation of collier docks, on the hitherto vacant north bank of the Thames, eastward of Bow Creek. The London Bridge terminus of the South Eastern and South Coast railways has been pulled down; the Companies have dissolved the partnership which had existed in respect to the use of that station, and an enormous expenditure is now being incurred in the erection of two new and distinct stations-an expenditure little short of a million sterling will ultimately have been involved in this station and its approaches. The South Western Company still make the Waterloo station their terminus: no progress having been made in the extension to the Borough. In the southern counties a few short branches have been opened. The North Kent line of the South Eastern, opened before the publication of last year's Companion,' has developed a large traffic, both for business and holidays. The Ashford and Hastings branch will shortly be opened; as also will a portion of the Tunbridge Wells and Hastings branch. The Reading and Reigate line has been finished and opened. The South Western and Great Western Companies have carried their respective branches into the very heart of Windsor, the one from Datchet and the other from Slough. Alton branch of the South Western has been opened as far as Farnham; and it has been lately decided that the remaining portion from Farnham to Alton shall be proceeded with. The broad gauge lines in the West of England have not lately made much advance: almost the only new opening having been a portion of the Wilts and Somerset Railway as far as Frome. An attempt is about to be made to revive the Taw Vale scheme (Crediton to Barnstaple and Bideford). The The Tyne and Tweed Railway Bridges:-So important are the means by which the east coast railways have been enabled to span the valleys of the Tyne and the Tweed, and so beautiful are the viaducts at those spots as works of engineering skill, that they call for a little separate description. When the Newcastle and Berwick Railway was planned, it was felt that a junction with the Newcastle and Darlington line could be effected only by the construction of a very lofty bridge over the Tyne at Newcastle; because the banks of the river at that spot are very steep, and the general level of the railways would not permit of a crossing at a relatively small height above the water. It had long been wished by the inhabitants to have a "high level" bridge, since the old bridge was adapted only for the low or water-side districts of Newcastle and Gateshead; and Mr. Robert Stephenson boldly planned a scheme which should meet this requirement, as well as the requirement of the railway companies. He drew up the scheme for a double bridge, with a railway line over a common road; the companies assented, an Act was obtained, and the works are now nearly, if not quite, finished. In order to understand the arrangement of this bridge, we must briefly notice the course of the railways through Newcastle. The Newcastle and Carlisle Railway had, till lately, its terminus at the western margin of Newcastle; the Newcastle and North Shields had its terminus in Pilgrim Street, near the eastern suburbs; the New. castle and Berwick started from the last named railway, at a point beyond the limits of the town; and the Newcastle and Darlington terminated at Gateshead, on the south bank of the Tyne. It was deemed advisable to merge all these termini in a new station on a magnificent scale, built in the heart of the town. This fine structure was illustrated and described in the Companion for 1850, p. 247. The Carlisle line has been extended beyond its former terminus, and carried on a bold curve to the central station; the Shields line (and consequently the Berwick line which runs into it) has been carried at a great height over Pilgrim Street and Dean Street, to the central station; while the Darlington line, shooting past its former terminus at Gateshead, is brought to the central station by the magnificen bridge now under notice. The Tyne bridge has two piers at the margin of the river, and four others in the stream itself; besides minor piers to support the land arches. These piers are of massive masonry. The distance from pier to pier is about 124 feet, and this determines the span of the arches. At a height of about 90 feet above the level of high water runs a level bridge for carriages, horses, and pedestrians; and at a further height of about 25 feet above this roadway runs the railway itself. The entire height of the masonry and iron work, from the bed of the river to the parapet of the railway, exceeds 130 feet. The whole length of the structure, from the high ground of Gateshead to the high ground of Newcastle, is nearly 1400 feet. There are nearly 5000 tons of iron-work in the structure. The masonry in and over the river has cost more than £100,000; the masonry and brickwork in fixing the land arches, about an equal sum; while the iron-work has cost a still larger sum. The Tweed bridge has been opened for traffic in the autumn of 1850, on the occasion of her Majesty's journey to Scotland. It is one of the finest and largest railway viaducts ever constructed. The old bridge over the Tweed was built in the reigns of James I. and Charles I.; it is nearly a thousand feet in length, and consists of 15 arches. When a junction became desirable between the North British and the various English railways, a viaduct over the Tweed was necessary; and Mr. Robert Stephenson planned the structure which has been lately opened. In order that the traffic might be accommodated, a temporary timber viaduct was built, to be used while the permanent viaduct was being constructed. This timber viaduct was itself a clever and even elegant structure; it was 1200 feet in length, and contained nearly 300,000 cubic feet of timber. The permanent stone viaduct consists of 28 circular arches, each 61 feet span, springing from lofty piers 85 feet broad. The total length is 2160 feet; and the greatest height, from the bed of the river to the parapet, is 126 feet. One half of the length is over the river; the other half is over the low shore on the south bank. The breadth between the parapets is 24 feet. The land portion of the viaduct has a graceful curve towards the east, on a half-mile radius. The roadway is on an ineline, ascending towards Berwick. There are 1,250,000 cubic feet of masonry; and 2,500,000 bricks. Southward of the viaduct there is an embankment more than half a mile in length, in some places 60 feet high, and containing 700,000 cubic yards of earthwork; so that the entire lofty structure to connect the English with the Scotch railway is very little short of a mile in length. The cost of the viaduct has been about £200,000. The Britannia Tubular Bridge: -But we have now to speak of a triumph of engineering which throws the Tyne and Tweed bridges -beautiful as they are-quite into the shade. It is a felicitous lot for one engineer, that his name should be associated so prominently with three such works-all in progress at the same time. It is a remarkable instance of the progressive advancement which marks the present age in all that regards mechanical invention, that the Britannia tubular bridge is intended to supply the place of-we may also say supersede-one of the finest bridges in the kingdom; and that the railway of which the tubular bridge forms a part, is in like manner a substitute for one of the finest mail-coach roads ever constructed. The road from London to Holyhead has been for ages regarded as the highway from the British metropolis to Dublin; and the late Mr. Telford was applied to by the Government, about thirty years ago, to devise the best means for perfecting this route. He did so; and the London and Holyhead mail-coach road, with its beautiful suspension bridges over the river Conway and over the Menai Strait, was the result. This noble road is now almost abandoned from end to end-at least for its primary purpose; since the Irish mails are now conveyed by railway, and Telford's route is used only for minor purposes. When Chester became a centre of railway communication, a few years ago, it was considered that a through route to Holyhead would be more conveniently established from that point than from Shrewsbury, which lies in the route of Telford's road. Accordingly the Chester and Holyhead Railway was constructed; and in its course, both the Conway and the Menai had to be crossed. Then came the question whether the suspension bridges would serve to carry the railway; and if not, what other means should be adopted. Many eminent engineers thought that Telford's bridges would suffice, provided trains proceeded over them at a slow speed, and were drawn over them by horses instead of locomotives, to lessen the weight; and we believe that such an opinion is still entertained, in many quarters entitled to credit. But in the golden days of 1845-golden in the visions of railway speculators-all such economical suggestions were slighted: both the Government and the public called aloud for something grander, and the railway magnates were not slow in responding to the call. Mr. Robert Stephenson, the engineer of the railway, taxed his ingenuity to devise the best mode of carrying his railway over the Menai (the Conway being obviously a more simple affair, from its much smaller width). The Admiralty required, as many vessels of large size are accustomed to traverse the Menai Strait, that the new bridge, of whatever kind it might be, should be constructed without the aid of that assemblage of large timbers which is called centering. Mr. Stephenson selected a spot in the Menai Strait, about a mile southward of Telford's Suspension Bridge, and where the width of the stream is about 1100 feet at high water. At this spot there is a rock called the Britannia rock near the middle of the Strait, the surface of which is about ten feet above the surface of low water, and ten feet below the surface of high water: so that it is above the water during about twelve hours out of the twenty-four. He made a design for a bridge of two cast-iron arches, with a central pier on the Britannia rock; and he laid his plans so that he could have built the bridge without centering, by employing tie-rods to connect the half arches on each side of the central pier. But here a new difficulty occurred. The Admiralty had required that the arches should have a clear height of 100 feet above high water; and Mr. Stephenson planned his bridge accordingly, with a height of 50 feet at the springing or bottom of the arch. The Admiralty, however, now demanded that the height of 100 feet should be maintained along the whole length of the bridge -a condition which could not be obtained without increasing the height of the crown or centre of the arch to 150 feet. This would have been incompatible with the general level of the railway. Hereupon it was determined to plan a straight or level bridge carrying a train either upon or within it. And here it is necessary to observe caution in attaching the name of any particular engineer to this wonderful work, in respect to the originating and carrying out of the principle of a tubular bridge. It is a painful incident in the history, that Mr. Stephenson and Mr. Fairbairn now put forth claims which are mutually irreconcilable, in regard to the honour which justly accrues from the noble enterprise. Both cannot be right; but we shall refrain from entering into the controversy, or into the paper-war which has marked it. The public have an earnest wish to give honour to both the claimants-to speak of Stephenson and Fairbairn in the same kind of honourable union as they would speak of Le Verrier and Adams. Suffice it for our present object to say, that both those gentlemen, and others who were subordinate to them, have worked out results which claim the admiration of all who can appreciate the nature of the difficulties to be overcome. As soon as it was decided that the bridge should be a hollow beam or tube, through which a train might be propelled, it had to be determined in what way such a tube might be made strong enough for the intended purpose. Should its section be circular, or oval, or square? Should it be of wrought or cast-iron? Should it be of equal thickness on all sides? The Railway Company supplied the funds for an extensive series of experiments, by which many remarkable and important points were elicited. The engineers were perfectly satisfied with the results, and a plan was arranged on the following basis:-that there should be two tubes across the Menai Strait, side by side, one for the up train and one for the down; that a lofty supporting tower should be constructed on the Britannia rock; that two other towers should be built, close to the Anglesea and Caernarvonshire shores respectively; that strong abutments should connect the tubes with the railway on either shore; and that each tube should consist of four lengths, viz. from the Caernarvonshire or east abutment to the east tower, from thence to the Britannia tower, from thence to the west tower, and from thence to the west or Anglesea abutment. A plan similar to this in all its chief details was adopted for the Conway Bridge, but smaller in dimensions; and both plans have now (November, 1850,) arrived at alımost entire completion. In the following descriptive details we shall speak exclusively of the Britannia bridge, except where the Conway bridge is especially mentioned. First, then, for the Britannia tower. The Britannia rock is formed of chlorite schist, a very hard stone, difficult of working; and as the rock is dry only for a few hours at a time, the labour and difficulty of forming the foundation of the stupendous tower were very great. The tower is built of hard carboniferous limestone, obtained from the Penmon quarries on Anglesea island; the stones were quarried |