A suspension railway, combining the characteristic features of Mr. Palmer's and Mr. Fisher's previously described, was patented by Mr. Maxwell Dick, of Irving, in Ayrshire, on the 21st of May, 1829; doubtless, in ignorance of those precedents, as we were personally assured by the latter patentee. The chief object of this gentleman was, as is stated in the title of his patent, "for the conveyance of passengers, letters, intelligence, packages, and other goods, with great velocity. The means which he adopts for this purpose, are designed to obviate the necessity and enormous expense of cutting and embanking resorted to on railways of the ordinary kind. The rail is supported, like Mr. Palmer's, upon vertical pillars, but carrying a double track for the carriages, like Mr. Fisher's. Mr. Dick has, however, added, what he denominates " safety rails," one on each side of the track, against which anti-friction wheels, attached to the carriages, are made to act, in case of the carriages receiving from any cause an impulse upwards. The patent likewise embraces a combination of wheel-work, for communicating a high velocity to the carriages.
A large and well constructed working model of this invention was publicly exhibited for several weeks at Charing Cross, London, in 1830, and drew crowds of visitors, who were surprised and delighted at the velocity with which the carriages darted along the wire rails across the room, by the application of a small force. The notoriety of this invention, as well as the capability of its being usefully applied under many circumstances and situations, for light loads at high velocities, seems to require from us something more than this brief historical notice. Accordingly we proceed to give a few, out of the many details and modifications, which the prolific mind of the inventor has thrown together in his specification. From this document we learn that the patentee especially designed his invention for traversing undulating, rugged, and abrupt ground, the crossing of rivers, mosses, marshes, etc. Pillars are to be erected of brick or stone with lime, at given distances apart, suppose fifty yards; between each of these may be placed four or five cast metal pillars, according to circumstances, for bestowing the requisite stability and keeping the rail free from undulations.
On the top of each of the pillars is to be fastened a frame, to which the rails are to be secured, and to the frames are connected grooved friction wheels or pulleys, between which the drag-line is conducted. The rails are to be made of the best wrought iron, such as is used for chain cables, and they are to be duly connected together in great lengths, and secured to the frames in such manner as to make the top surface smooth, and free from all obstruction to the motion of the carriages. Between each frame there are to be introduced three or four cast-iron braces, to prevent vibration and stiffen the structure. The method proposed for dragging the carriage along the railway, is by fixed or stationary engines acting with drag-lines or ropes attached to the carriage, which, if the railway be double, (as in the subjoined illustration) will act in an endless round; but if the line of railway be single, then the engine will be nterchangeable and reciprocal.
Fig. 1 represents aside elevation of one span of a double suspension railway, supported at the extremities by a pier of masonry, d d, and at equal distances by four cast-metal pillars e e e e. a is the upper or "bearing rail;" b the lower or "safety rail," which are bound together by intermediate stay braces, better shown on a larger scale atff in figures 2, 3, and 4.
Fig. 2 shows a front elevation of a frame c c c, for a double line of rail, with a carriage on one of them at g. The letters of reference in this figure, as in all the others, designate similar parts;.it therefore need only be said, that the stay braces ff are seen in section between the rails a b.
Fig. 3 gives a side elevation of a carriage on a portion of rail; h h h being the running wheels, and i i i the anti-friction rollers, which prevent the carriage from being thrown off the railway. An examination of Fig. 2, which exhibits the end view of this carriage, will fully explain its form and construction.
Fig. 4 is a perspective sketch of one of the stay braces on a larger scale. The expense of one mile of railway on this principle is calculated at 1395l. 10s.6d. The advantages contemplated are stated by Mr. Dick as follows: "In the first place, as you save distance, so do you save time; which all must admit, that in a commercial as well as in a political point of view, is of the utmost importance. The suspension rail takes a straightforward point from one town to another, without regard to the surface of country over which it has to go, whether rising or falling, crossing of rivers, or otherwise. All are, by regulating the heights of the pillars, with the same ease gone over, and by that means saving of distance, saving of surface ground, saving bends in the formation of the rail; which bends, besides the extra expense of originally laying, are always liable to great derangement from the lateral friction of the waggons coming round them, compared to that of a straight line of rail. Secondly, the suspension railway, over that of the ground railway, has another immense advantage; that is, as far as expense is concerned, which is, in the saving of all embankments, excavations, building of bridges, cutting of tunnels, besides the great breadth of surface ground.