able to obtain, it was here also that Rail-ways of that material were first constructed. It appears; from the books of this extensive and long-established Company, that between five and six tons of rails were cast on the 13th of November, 1767, as an experiment, on the suggestion of Mr. Reynolds, one of the part

I think there is every reason to believe that the latter is the more probable term of the first introduction of cast-iron rails. In the first place, iron wheels were not used until about 1753, and at that time only very partially; it was not until several years after, that they came into general use-so long, therefore, as wooden wheels were made use of, we may suppose cast-iron rails had not been invented:

Mr. CARR, in his Coal Viewer and Engine Builder, published in 1797, says, "the making and use of iron Rail-roads were the first of my inventions, and were introduced at the Sheffield colliery, about twenty-one years ago." This would make the date of their introduction about 1776, which is subsequent to that of Colebrookdale.

Fig. IV. Plate I. Represents the form of Mr. Carr's cast-iron rails, which were used under-ground at the Duke of Norfolk's colliery, near Sheffield; a a a a, are the rails, which were six feet long, and in the form as shewn in Fig.

V.; near each end of the rail small holes were cast, through which a nail was driven into the sleepers, which was of the same description as those of the wooden rails, Fig. II., and shewn by the dotted lines in Fig. IV.; at the joinings of the rail at cc cc, they were merely laid against each other at the ends, and nailed down to the sleeper, the intermediate sleepers having only one nailing; Fig. V. shews a section of this form of rail; ab, the horizontal bearing in which the wheel travelled; and b c, the upright ledge or projection to prevent the wheels from running off the road.

Various forms of this rail, which is called the "Plate Rail," appear to have been used with either wooden sleepers stretched across the whole breadth of the Rail-road, or short square wooden sleepers, as shewn in Fig. IV., on which the rails were nailed. In the year 1800, we are told that Mr. Benjamin Outram, an engineer, in adopting this rail on the public Railway at Little Eton, in Derbyshire, introduced stone props instead of timber, for supporting the ends and joinings of the rails.

Mr. Outram, however, was not the first who made use of stone supports, as the late Mr. BARNS employed them in forming the first iron Rail-road which was laid down in the neighbourhood of Newcastle-upon-Tyne, viz. from Lawson main colliery to the river, in 1797.

This kind of rail has undergone many alterations in form since it first came into use.

Fig. VI. Plate I. is a ground plan; Fig. VII, a side

view; and Fig. VIII. a section of the most improved form of this kind of rail;-cc cc are the rails, four feet long, placed upon stone supports, about a foot square, and eight inches deep, as shewn in Figs. VI. and VII.; at the ends of each rail, when they are laid against each other on the stone support, a small square piece is cut or left out in casting the metal, increasing in size upwards, so that, when the two ends are laid together, these two holes form a sort of square hole through the ends of the rail, narrowing downwards; a perfectly level and horizontal groove is then made on the top of the stone, and the rail imbedded in it ; a hole, corresponding with the square hole of the rails, is drilled into the stone, about half the depth; an iron pin is then driven into the stone through the hole in the rails, which having a bevilled head fastens them down to the stone, one half of the pin securing one rail, and the other half the adjoining rail, as shewn in the drawing; these nails are generally from three to four feet long.

Fig. VIII. is a section of the rail; a d, the bottom or wheel-track, about four inches wide and an inch thick, which is made quite level; d e, the flange or upright ledge to keep the wheel upon the part a d of the rail, and a fa, the flange projecting downwards to strengthen the rail; the upright flange is the same height throughout the whole length of the rail, as shewn in Fig. VII. being no higher than is necessary to secure the wheel upon the proper track, and which of course requires no greater depth in one part than another, and the height adding to the friction of the carriagewheels, it will necessarily be made as low as possible; hence we find it never exceeding three inches. This restriction in the height of the upright edge limits the form of the section, and renders it not that of the greatest strength; the resist ance to fracture being as the breadth and square of the depth, the horizontal part a d of the rail, while it adds to the cost,

does not in the same degree add to the strength; the upright section di, being the only part in that position which presents the strongest form of section; this, however, as previously stated, being limited in height or downright projection, has been cast upon the opposite side of the buoying section of the rail, shewn by a f, Fig. VIII. and a fa, Fig. VII., the form of this, as shewn in the latter figure, is such as to secure equal strength in every part of the rail, being deeper in the middle, f, and tapering away in a parabolic or semi-elliptic form, in both directions, to the ends of the rail.

This form of rail, with very trifling modifications, constitutes the most modern plate rail; until very lately they were universally made of cast-iron; but, about a year ago, some were formed of wrought-iron; the latter have as yet, however, been very partially used.

Soon after the introduction of cast-iron rails, a form of rail, called the " Edge Rail," was brought into use. Mr. W. JESSOP, in 1789, formed the public Rail-road at Loughborough with this kind of rail; the upper surface of which was of an elliptical figure, with flanges upon the wheels to guide them upon the tracts of the road.

In the wooden Rail-ways, the upper rails were convex on the surface, and upon one side of the periphery of the wheels a flange projected downwards about an inch, which served to keep the wheels upon the rail; when the plate-rail was introduced, the form of the peri

phery of the wheel would be altered, being made quite flat and of less breadth; and, the rim of wheel, for the edge-rail, was again brought back to the same form as that for the wooden Rail-road.

Fig. IX. Plate I. Represents an elevation or side-view of the edge-rail, as mostly used in late years, which consists of a bar of cast-iron, from three to four feet long, and about one-half or three-quarters of an inch thick, swelling out at the upper part to two or two inches and half broad, for the wheel to run upon, and placed upright, within a sort of chair, upon the stem supports. These rails, when first used, were not secured upon the stone or wooden sleeper by a separate chair or pedestal, but had a flat bearing projecting outwards, on each side, at the end of the rail, through which were square holes for the pins or nails to pass, that fastened them to the sleepers.

It is evident that this form of rail combines the greatest strength with the least expenditure of material; for, being placed upright, they present the greatest depth in the direction of the stress or strain upon them. The form first used was nearly a parallelogram. Fig. III. Plate II. will show a section of those at present used, the breadth of the upper surface, a, is about two inches and a half; after keeping this breadth a little way down, as shewn in the drawing, they gradually diminished to three-quarters, tapering down to half an inch, near the bottom at c; this was the section of them for a long period, but

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