Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/216

 200 THE BUILDING NEWS. Marca 8, 1872. —as the length of flat is 16ft—makes the distance between centre of each to be 2ft., and the number of pieces of lead 8.* Before cutting out the lead the size of rolls must also be settled, assome allow 3in. and 4in, for roll, and others 24in. and 3jin. I shall, in this ease, take the latter, which causes the breadth of each of these eight pieces to be 2ft.+ 2hin. + 3Jin. = 2ft. Gin. ; and the length 12ft. + din. + 2in. = 12ft. 6in. The extra 6in. in the latter is for the overlap and turn in—or “clinch ”—ateach end. The first thing to be done, in putting on the above lead cut out, is to nail on the long narrow 4in. lead strips all round edge of flat with 1}in. flat- headed nails, leaving top of lead to project up nearly 2in. as per Z, Fig. 23. Then in front of this put on the lead flashing—cut out at 1ft. broad—as per dotted line, Fig. 23. Its top edge being nearly on a level with top of flat, about 3in. is taken up by perpendicular upstand, while the other Yin. lies down on roof. These flashings overlap each other at the four corners of flat. Both the flashing and the narrow strip of lead, or “clinch,” at its back, are held by nails driven in as at Y, Fig. 23. After flashing has been all properly fixed and dressed, the upstanding lead at Z, Fig. 23, is then turned down level with top of flat as per Z, Fig. 24, and its outer edge planed straight. The situation of rolls is thenmarked off as per Fig. 25, which shows longi- tudinal section of flat. Then one of the 12ft. 6in. x 2ft. Gin. pieces of lead is taken, and after being rolled out across flat and dressed, it is set up (@e. turned up) all along each side as per A, Fig. 25, the up- stand at one side being 23in. and at other side Shin. high. Another 12ft. Gin. x 2ft. Gin. piece of lead is taken, rolled out, and set up in same manner, and then put close alongside the former piece as per B, Fig. 25, the side with 24in. upstand of B being next the 33in. upstand of A (the top of 24in. upstand of B haying been planed straight before being placed close to it.) The upper part of 3}in. upstand of A is turned over B as per I, Fig. 26, the seam being beat close. ‘The lead is then beat down all along seam as per J, Fig. 27, and so the first lead roll is formed. The same process is repeated with lead at C, the 34in. upstand of B turning over on 2hin. upstand of C; the same with D and E ; then back to F. Where several hands are at the work, one portion may be doing F, G, H, while the other is at C,D, E. The 3}in. up- stand of F folds over the 24in. upstand of A, and so on with G and H, only in the case of E and H their outer edges have to lap over the lead shown at Z, Fig. 24, and to be folded in, or “clinched,” as per K, Fig. 28, and then bent down as per L, Fig. 29, and beat quite close. What is done to ‘‘outer edges,” or sides, of H and E, as per K and L, has also to be done to the ends of H and E, as also to the ends of all the rest, and at the same time ; and, in addition, both ends of the seven rolls have to be bent down about 2in. over edge of flat. In bending or working these rolls down over edge of flat, as per M,N, Fig. 30, some can do so without stuffing them, others, again, prefer to stuff ends of rolls before beginning to turn them. This stuffing is done by taking a piece of sheet lead about 9in. long, and rolling it up firmly to the thickness of one’s little finger or so, and then slipping this into roll ; the roll is turned down with stuffing in it. When being turned down a small portion of end of roll which is too long is cut off. While working these rolls one of the wooden dressers, cut out to the shape and size of rolls, as per O, Fig. 31 is generally used. In order to tie down these lead rollsalong their length, lead latchets or ‘clips ” are put inside roll. These latchets are simply pieces of sheet lead, about Sin. long, and 3in. or 4in. broad, cially as any cuttings are not lost, but melt up again, While I have taken the distance between rolls at 2ft., some may make it 2ft. Gin., but the former is best for lead, and in some cases the distance may be 1ft. Yin. or lft. Gin. which are fixed on top of flat, as per Fig. 52, with screw-nails ; 2in. on flat, and 3in. up- stand ; they are put on every 4ft. or so, the upstand going inside seam, as between A and B, Fig. 25; and as B on that side only stands up 24in., while the latchet is Sin. high, the top of latchet is bent down over B, and in order to leave no mark in the seam, the thickness of latchet lead is cut out of B’s 2kin. upstand ; and, of course, as the lead is being turned over to form roll, Fig. 27, the latchet is turned with it, and perforce takes same shape, being inside it. The 2in. of latchet, which is fixed to wood of flat,is sunk down in wood the depth of its own thickness —yiz. about one-twelfth of an inch. As this latchet goes between A and B, Fig. 25 (and in all the rolls—say two to each—which gives fourteen latchets) it is, of course, fixed on before A and B, &c., are brought together. In this style of covering flats with lead, no wooden batons are required at all, while the lead is left quite free to expand and contract. In turning over the rolls they should always be turned towards the side which is least ex- posed to the wind and rain. In beginning to lay the lead on the top of flat—although in Fig. 25, I have, for the purpose of illustra- tion, began in the centre with A and B—the plumber may begin at side—viz. at HE, Fig. 25, and in turning rolls, he must be careful to keep them all straight and even. Fig. 33 is sketch of flat when finished and covered with lead, as above described. Next article will explain the manner of using zinc for flats, the use of saddles along centre of flat, &e. (To be continued.) —— ARCHZZOLOGICAL. Avesury.—Some time since, in the columns of Nature, some allusions appeared to the threatened destruction of one of the most notable megalithic monuments in this country, the Great Circle at Ave- bury, in Wiltshire. All archeologists will be glad to hear that Sir John Lubbock has purchased the site on which the Circle stands. Remarns or LAke Dweriines.—On the borders of Lake Leman, almost opposite Nyon, there has recently been discovered a lacustrine station, which appears to be very rich in curiosities of prehistoric times. This station is situated on the gulf of Condrée, near Thonon; the piles cover a considerable space, and the importance of this lake settlement seems to have equalled that of Morges, which faces it on the Vaudois shore. In the course of one morning's ob- servations there have been collected seven hatchets, two knives, two sickles, one lance, five bracelets, and a large number of pins, all in bronze. The waters being low at this season remarkably facilitate re- searches of this nature. Accordingly these anglers of antiquities have taken good hauls of late at Eaux-Vives, at Hermance, Vernier, Versoix, and Nyon. In this last locality they found last week a bronze harpoon of an admirable configuration. This object is probably without an equal in lacustrine collections. ——~»—— CHIPS. Sir Henry Holland, Bart., President of the Royal Institution, has accepted a vice-presidentship of the Society for the Encouragement of the Fine Arts. The City Commissioners of Sewers have resolved upon the construction of a room for infected articles, a room for the storage of articles after dis- infection, a shed for a truck, and a furnace for burn- ing infected flock, &c., on the ground in Golden-lane, purchased for mortuary buildings, &c. Mr. Roddis, of Birmingham, has a very richly- sculptured reredos in course of execution for 8. Peter’s Church, Chichester. We learn from Art that in future, instead of the artistic work at the Sévres manufactory being executed, as heretofore, by a few painters and model- lers attached to the establishment, it will be thrown open, and orders given for what is required to various artists, At a meeting of the Articled [Law] Clerks’ Society, held at Clement’s Inn Hall on the 28th ult., Mr. Il. Lewis Arnold presiding, Mr. Dendy opened the subject for the evening’s debate—viz., “ That the interests of all persons entitled to inclose com- monable lands near London, should be purchased by the Government for the benefit of the people.” The motion was lost. Civil Engineering. ON THE NORTH LONDON RAILWAY (CITY BRANCH).* in North London Railway proper was originally designed as a line for goods only, and was con- structed under the powers of an Act of Parliament dated Aug. 26,1846. As its name then implied— “The East and West India Docks and Birmingham Junction Railway”—it was intended to form a con- nection between the docks at Poplar and the London and North Western Railway (at that time known as the London and Birmingham Railway) at Camden Town, and thus complete a through communication for goods and merchandise from the manufacturing districts in the north-west of England to the ship- ping portion of London. At that time there was no intestion whatever of making it a railway for the conyzyance of passengers; it was, however, soon found that a large number of persons would use the line as a means of transit from place to place in the northern suburbs of the metropolis. By means, there- fore, of a branch line from Bow, communicating with the Blackwall Railway at Stepney, passengers were conveyed to Fenchurch-street Station. The power authorising the construction of this connecting link was obtained in 1850, and was entitled “The East and West India Docks and Birmingham Junction Railway Branches and Amendment Act.” This route, however, was found to be very circuitous, especially for passengers coming from Camden Town (and, indeed, from all parts west of Hackney) to the Bank of England, &. An Act of Parliament was therefore obtained, dated 22nd July, 1861, empowering the North London Railway Company to make a branch line direct from Dalston to the City, by means of which a saving of four miles was effected in the route from Camden to the City, the distance from Camden to Fenchurch-street, via the North London proper, being nine miles, whilst from the same place to Broad-street Station, via Dalston Junction and the City Branch, the distance is only five miles. Assuming that the Bank of England is, for all practical purposes, the centre of the City, the distance from the centre, either to Fenchurch-street or Broad-street stations, is as nearly as possible the same, although really about nine chains’ length in favour of the latter. There is now, however, a shorter and more direct. route from Camden and its neighbour- hood to the City, vid the Midland and Metro- politan Railways, to Moorgate-street ; the distance being only three miles. It was not without some trouble and a good deal of consideration that the route finally selected and adopted for the City branch of the North London Railway was decided on, and, though at a first glance at the map it would appear that the west side of the Kingsland-road ought to have been adopted, as giving not only a shorter and more direct route to Broad-street, but also avoiding the necessity of crossing under the Kingsland-road at Dalston, and re-crossing over the same road, near Shoreditch—at both of which points the works were exceedingly heavy--there were other and weightier considerations which induced the engineers to come to the decision of carrying the line up the east side of the Kingsland-road, Foremost among these considerations was the interference with, and damage to, the properties known as the De Beauvoir estate, and the large and valuable wharves on the banks of the Regent's Canal, neither of which could have been avoided had the line been carried on the west side. Another matter which involved serious consideration was whether the line, after passing Thomas-street, should be continued so as to cross the Kingsland-road and Old-street-road with one bridge, by which two of the heaviest wrought-iron bridges on the line and a sharp curve would have been avoided, and a better position obtained for the Shoreditch Station ; but a strong ana powerful oppo- sition was threatened if the line was brought nearer to Shoreditch Church than its present position. Almost the entire site of the railway was covered with houses, which were, of course, purchased and pulled down. There were no so-called engineering difficulties of any sort, but the foundations of the piers of arches, and the abutments of bridges, had to be carried down in many places to a great depth. From Dalston to the Regent’s Canal the average depth was 7ft. 6in. below the surface; thence to Worship-street, 15ft. Gin. ; and from there to Broad- street Station about 20ft.; some of the piers at Broad-street being as deep as 26ft. Gin. The City branch diverges from the main line of the North London Railway near King’s-road Bridge, a short distance to the west of the old Kingsland Station, ee Engineers’ Society, on Friday evening last, March Ist, by Mr. W. Lawrord, M. Inst. C.E, as oR —
 * In cutting out the lead, do not scrimp it more espe-
 * Abstract of paper read before the Civil and Mechanical