1849.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



201 



Mr. Adams said, that these wheels were made with two wrought. iron 

 discs riveted to a ring of T-iron to form the inner tyre, and riveted to the 

 two faces of a cast-iron nave which was turned to receive them ; they had 

 been in use eight years, and he thoiiijht they would last many years, and 

 were as good wheels as the one under consideration, and much cheaper ; he 

 did not know why there had not been more of them made. 



Mr. Smith observed, that by forging the tyre solid on the wheel, the risk 

 of accident from the breaking of the tyre would be avoided whilst the origi- 

 nal tyre lasted; and he thought that advantage was worth ensuring, as many 

 accidents had been caused by the tyres breaking or coming loose. 



Mr. Beyer asked whether the wheels were all as good as the specimen 

 exbil)ited to the meeting, and whether the two moulds of which the wheel 

 was made were always perfectly united at the outer face of the tyre. 



Mr. Smith said, he would guarantee the wheels to be all as good, and the 

 moulds were united as thoroughly and soundly in the forging as the bars in 

 piled iron. 



Mr. Slate asked if he could tell what would be the probable wear of 

 these wheels; but Mr. Smith said there had not been sufficient experience 

 of their working to ascertain that. 



Mr. Allan remarked, that the disc part of the wheel was almost ever- 

 lasting ; it would last 100 years, but the tyre would not last more than 3 

 years. 



The President said, it was certainly a very good wheel, independently of 

 the question of the tyre ; and he was of opinion that the railway world was 

 very likely to be greatly indebted to Mr. Smith for his very excellent wrought- 

 iron wheel, and he saw no reason why it should not come into extensive use. 

 Aliout the tyre he had yet some doubt whether it was desirable or essential 

 for the sake of a small portion of additional safety for two or three years, 

 to forge the tyre solid with the wheel. He thought the mode of manufac- 

 turing the wheel was highly interesting, and it was a triumph in forging that 

 be was not prepared for. 



RECLAMATION OF PEAT BOG. 



{WithEiitjraviiigs, Plate XIII.) 



On the Origin and Rpclamation of Peat Bog; vnth some Observa- 

 tions on the Construction of RwtiJs, liai/ii-ays, and Canals in Bog. 

 By Bernard Mvli.ins, Esq., C.E. Vice-President of the Institute 

 of Civil Engineers of Ireland; and M. B. Mullins, Esq., A.M., 

 C.E., Member. 



The following interesting paper is an abridgment of one read 

 before the Institution of Civil Engineers of Ireland. Its great 

 length precludes our giving the introductory part : it chiefly re- 

 lates to agriculture, and may be seen in the Transactions of the 

 Institution. 



Boads in Bog. 



Good roads and navigable canals through bogs aid so much in 

 the process of reclamation, and have proved such stumbling-blocks 

 to projectors generally, that it is not inappropriate to make a few 

 observations on these subjects. 



Hardness and smoothness of the surface are the chief objects to 

 be obtained in road making. The elasticity of the soil offers a 

 great impediment tp the attainment of these qualities; we there- 

 fore must calculate on considerable difficulties in making a bog road 

 unless managed with skill; indeed, when practicable at a cheap 

 rate, the peat should be entirely removed. However, as this could 

 not be done in the great majority of cases, we must have recourse 

 to other means; and although the elasticity of a bog can hardly 

 ever be destroyed, as may be seen by the shaking of the water of 

 the drains when a vehicle passes along the oldest roads of that 

 description, yet, if brought to a uniform and even bearing, and not 

 liable to those alternate ups and downs which are almost always 

 met with, the perfect flatness which is attainable compensates 

 much for the impediment produced by its elasticity. 



In every line of public road through deep bogs, drains should 

 be made, 63 feet apart, enclosing the site of the road; and paral- 

 lel and external to these a catch-water drain at either side, at a 

 distance of 21 feet, thus occupying five plantation perches, as 

 shown at Plate XIII. fig. 1. 



This great breadth of enclosure is necessary, in order to ensure 

 the drainage to an extent sufficient to give bearing and stability to 

 the elastic seat of the road; cross drains, will, in most cases, be 

 necessary, at a distance of say two perches asunder, leading at 

 right angles into the fence drains. The whole of these drains, 

 being made to such dimensions as the state of the bog will pre- 

 scribe, should be repeatedly widened and sunk, and the spoil of 

 the side drains thrown on the ramparts, or 21 feet spaces; when 

 the enclosures shall become sufficiently firm, the cross drains are 

 first to be filled-in with the bog material taken out of them, and 



the spoil that had been heaped on the ramparts to dry, should be 

 wheeled in barrows to make the base or convex bed of the road, 

 which should be raised in the middle 2 feet in the first instance, to 

 admit of subsidence, and formed gently sloping on either side. The 

 breadth of this formation may be for public roads 30 feet, and for 

 accommodation roads 20 feet; for the latter an enclosure of four 

 perches in breadth will be sufficient. Great care should be taken to 

 have the bog material well chopped and trodden. If the spoil be 

 insufficient to form tlie bed of the road as described, additional 

 material may be had with most advantage by widening and sinking 

 the side di-ains, particularly the catch-water or outside drains, 

 which, besides carrying oft' the surface-water of the adjacent bog 

 at a distance from the road, will tend materially, by the more rapid 

 drainage and consolidation of the ramparts, or 21 feet spaces, to 

 resist the subsidence of the seat of the road which becomes, as it 

 were, propped on either side by banks of solid peat. 



In wet bogs it will be necessary to continue the gradual opera- 

 tions described, for about two years before the road material can 

 be put on. At the expiration of that time, a soaling of stiff clay, 

 from 8 to 10 inches in depth, should be laid on, and over this a 

 covering of finely bi-oken stones or gravel, about 8 inches in thick- 

 ness. 



If partial subsidence of the road should take place, a frequent 

 occurrence from insufficient drainage, the road material should be 

 taken up, and the sunken parts raised with dry bog-mould, firmly 

 punned or trampled, the soaling and metalling may then be again 

 laid on. The common practice of raising the sunken parts with 

 heavy road material is an error, for the tendency to sink is thus 

 greatly increased. It is, therefore, obvious that uniform pressure 

 is one of the chief objects to attain in bog road making. 



Where sufficient time is not allowed for consolidation by drain- 

 age, a foundation is made with a layer of brushwood, or the slen- 

 der branches of trees which are tied up in bundles 10 or 12 inches 

 in diameter, and 10 or 15 feet long; these, known by the name of 

 fascines, are much used in Holland, and are laid firmly bound toge- 

 ther in alternate transverse and longitudinal layers; over these a 

 covering of earth is placed, and then the pavement or metalling is 

 put over. 



This mode, as may be inferred, is not so good, and is greatly 

 more expensive than that recommended by us, and is only to be 

 had recourse to in particular spots where drainage is extremely 

 difficult, or in railroad making, where sacrifices are made to save 

 time; but no expedient ought to supersede a system of proper 

 drainage whether for railways or other roads — in the former a 

 "grillage" of cross timbers of large scantling and longitudinal 

 bearers will be the best mode of sustaining the rails, and it will be 

 found that the elasticity of the road, if made of the bog material 

 as described, will tend greatly to its stability and cheapness of 

 maintenance, there being no tractive contact as in common roads 

 with the surface. Bundles of furze or heath are sometimes used 

 as fascines in passing a road over a quagmire, but they are a mere 

 temporary expedient, and in every respect inferior to those made 

 of small branches of sufficient length, made in the manner subse- 

 quently to be described. 



In dry shallow bogs catch-water drains may not be necessary; 

 with this exception, the same system of making is applicable in all 

 cases. 



M'liere rivulets and streams are intercepted by the line of road, 

 they should be passed under it by suitable culverts, which, if built of 

 stone or brick, would in many cases be a work of much difficulty 

 and expense in the carriage of building materials, sinking founda- 

 tions, and keeping out water during their construction. These 

 considerations suggest the expediency of making culverts of 

 wood (Plate XIII., figs. 1, 2, and 3), siich as we had recourse to 

 with effect in the execution of the Ballinasloe Canal, twelve miles 

 of which pass through deep bog; the sides to be formed of round 

 native timber piles, 9 inches diameter, adzed off on one side to re- 

 ceive the sheeting, lightly shod, hooped, and driven firmly into the 

 hard, to the depth of 2 feet under the lowest assumed level for the 

 ulterior drainage of the district. Two rows of these piles to bd 

 driven in the line of the waterway, 4 feet apart from centre to 

 centre, and 4 feet from each other in the longitudinal direction; 

 three rows will form a double culvert. 



Transverse capping pieces, of 9 inches by T inches to be notched 

 down on the heads of opposite piles, as per sketch, and bolted to 

 them with sufficiently jagged bolts; longitudinal sheeting of saw n 

 elm or beech plank, 3 inches thick, to be laid closely together on 

 these capping-pieces to which they are to be spiked; the sides to 

 be sheeted in like manner, from the level of the capping to the 

 bottom of the watercourse, with round wood of not less than 7 or 

 8 inches diameter, having one cut through the middle longitut'.i- 



27 



