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10f> THE CIVIL ENGINEER AND ARCHITECTS JOURNAL [April, drawn by 3 horses, were passed over them ; this roller was constructed on the Polonceau principle, and made of wood lined on the inside with lead, and the outside covered with sheet iron, and filled with sand; it weighed 3 tons. Interior Slopes.—In ordinary canals the exterior slopes are frequently of earth turfed, and if they have stone or timber facing at any point it is generally in those places where there are wharfs, however, on the Birmingham Canal stone and timber facings have been sub stituted in the upper part for earth banks, the slopes having been preserved below the surface of water as a counterpoise to the masonry and timber work, this method shown in section fig. S, allowed the wharf walls to be made thinner, and the stakes or piles of the timber facing to be reduced to a minimum length. Thus the foundation of the masonry hardly goes down to the level of the bottom of the canal, and the piles are not driven to a greater depth, these piles are placed from 3 to 4 feet apart from centre to centre, and have a cap ping or campshed 7 inches square, which serves as a support to the planks placed behind to keep up the ground between one pile and another; these timber facings are very simple and very cheap, and may be made at all seasons without forming a coffer-dam, or laying the canal dry. Jlrdrossan or Paisley Canal. The section of this canal is shown in fig. 0, the breadth at top is 35 feet, depth below the ordinary surface of the water 4 feet, and G feet, from the top of the banks to the bottom. The banks are faced with stone as shown in figs. 9, 12, and 13. In section fig. 9, the stone facing is laid 16 inches below the water surface, and 12 inches above; it is constructed with 4 courses of rough stone laid dry and scabbled on the face, the lower course projects forward, and small stakes are driven every 2 fept at the base, to protect the stone work. Section fig. 12, is constructed in a similar manner, excepting the stones are larger and in 3 courses, and have no stakes to protect the foundation. Section fig. 13, has 4 courses of large stones ns fig. 9, but they are set like steps. These two last sections were only tried by way of experiment, that which is now adopted is shown in fig. 9, it gives the greatest re sistance, and is best calculated to deaden the action of the waves, or surge of the water, and at the same time the most economical. Forth and Clyde Canal. This canal has a mean breadth of GO feet at the top, and 8 feet deep below the water surface, and 12 feet deep below the top of the bank; different methods of lining the banks have been adopted to prevent the abrasion of the banks by the action of the water, occasioned by the establishment of quick passage boats, as shown in sections figs. 10, 15, 16, 17 and 18. On the towing-path bank of section fig. 10, the facing is laid in the same manner as in fig. 9, of the Ardrossan Canal, except ing the courses of stone are more numerous, and there are no stakes to protect the foundation. On the opposite bank, as those points most likely to be affected, they are cased with rubble work. Section fig. 15, shows a broad bench at the bottom, and the stone facing laid on a slope of 45°, which is carried up to one foot above the water surface. Sec tion fig. 18, the stones are laid on a slope and continued up to the top of the bank, which is capped with a fiat stone 1 foot 8 inches wide. Section fig. 16, shows another method of construction, the stones are laid to the form of the curve of degradation; the stone work does not extend more than 12 to 15 inches below the water level, and the same same height above. Section 17, consists of 4 courses of basalt, each 10 inches high and 1 foot 8 inches to 2 feet deep, it is carried up to the top of the bank, the top course oversailing at the back, and forms the fender. These different systems of stone facing for banks have been tried on a scale sufficiently large to form a tolerably correct judgment as to their expense and efficiency. The last section fig. 17, is evidently the best, but the cost is very- high, and the same may be said with regard to section fig. 18, besides neither of these two last sections have the advantage of deadening the effects of the wave. The section ultimately adopted is that shown in fig. 10, its cost is 2s. 4d. per yard forward. The Union Canal. This canal has a breadth of 40 feet at the top, and a mean breadth of 37 feet on the lino of the water surface, the depth below this line is 5 ft. 3 in. and 1 ft. 6 in. to 2 ft. 3 in. more to the top of the banks. This section, as will be presently described, is more favourable for passage boats than the section of the Forth and Clyde Canal. It is on this canal that stone facing have been adopted to the greatest extent since the establishment of passage boats, and on which circum stances have been most favourable for this description of traffic. The same systems have been tried as on the Ardrossan and the Forth and Clyde Canals, but the nature of other materials on the spot have caused the adoption of a different system for those canals, more simple in operation and better adapted to effect the end proposed. The section fig. 11, shows the stone facing of the bank, it is nearly similar to those of the Forth and Clyde Canal fig. 10. On the towing-path bank there is however a slight batter or inclination given to the facing, and also ou the opposite bank are laid large pebbles placed irregularly to a certain thickness, instead of rough stone. A considerable length of bank is faced with stone, as shown in sec tion fig. 18, of the Forth and Clyde Canal, and another system has been tried similar to section fig. 19. But the facings adopted and generally followed are those shown in sections figs. 20 and 21. In section fig. 20, stone slabs of different lengths, from 28 to 32 inches wide, and 2i to 3 inches thick form the facing, they are sunk into the clay puddle of the bank: it was found that the upper part of the faeing was not sufficiently firm, consequently another narrow slab was laid on the top horizontally, ns shown in fig. 21, which prevented the pressure of the earth against the top of the facing, and made a base for the turfing of the slope of the fender. The facings of the towing-paths on the banks of the Union Canal, between Falkirk and Edinburgh, have been made the same as the two last methods just described, nearly throughout the whole length, and in some cases the opposite bank also. This description of facing has an ex cellent effect, both as to appearance and as to its operation on the waves of the canals. The joinls being well secured, no water can get in to injure the bank, and this plan which gives the best appearance to the work, is in leality the most economical, the cost being only from 2s. 6d. to 3s. per yard forward, while the work in fig. 11, costs from 3s. to 4s. The reason for this cheapness is the abundant supply on the spot of a slaty stone well adapted for the purpose. Canal dt L’Ourcq. The canal de l’Ourcq had already suffered very much from the ac tion of the water, on the two banks between la Villette and Claye, when it was proposed to run passage boats upon it. It therefore be came necessary to repair the banks, and the expense of stone facing- on the English plan, and the want of good materials rendered a distinct course necessaiy. The canal company having a large quantity of brushwood and cuttings, wished to have a trial made to protect the banks with fascine work, as in section fig. 5. Stakes of oak 4 inches thick were therefore placed at every twenty inches distance, and driven into the ground 2 ft. 3 in. to 3 feet deep, and fascines placed behind them. It was soon found, however, that the fascine work was ineffective, as the water got in during the undulations, and on retiring carried away the earth. The fascines have therefore been removed, and oak planks laid behind the stakes, as shown in fig. 14. This plan, there is every reason to believe, will prove cheap and work well. On other parts of the works another plan, as shown in figs. 2 and 7, has been adopted, like that on the Ardrossan and Forth and Clyde Canals. The works however get on slowlv on account of the difficulty of finding stones large enough. RAILWAYS BILL. Since our last number, Mr. Labouchere’s bill has made farther pro gress, and such is the want of effective opposition, that it would doubtless have passed through all its stages by this time, had not Sir Robert Peel interfered to get it referred to a select committee. From this committee, however, we expect little good, although Sir Frederick Smith is said to have been sorely discomfited in his examination by Sir Robert Peel, when his incompetency was shown so fully as to have been convincing to the minds of unprejudiced persons. Mr. Labou- chere felt this, and was in the greatest possible rage, so that, to cool himself, he endeavoured to harrass several of the witnesses in such a manner as to call down the remarks of the chairman, although he effectively succeeded in frightening some parties. The opposition, as it is called, which is now being carried on, pro ceeds from a committee of the delegates of boards of directors, who have overstepped their powers, and are disunited among themselves. Several of the chief of the delegates are, indeed, publicly charged with giving underhand support to the Government plan, while they throw every obstacle in the way of those who attempt to carry on the opposition in earnest. From such parties no good can be expected under any circumstances, and we need scarcely say that they are
