Page:Journal of the Asiatic Society of Bengal Vol 1.djvu/585

1832.] XI. — Progress of Mechanical Science. 2. Iron Suspension Wheete.

[Note accompanying the model presented to the Asiatic Society, by Lieut-Colonel Watson, 3rd Oct.]

A description of the great improvement in the construction and principle of wheels for carriages of all sorts lately introduced by Mr. Theodore Jones, will be found in most of the journals of mechanical inventions at home ; but as such works are not frequently to be met with in India, I will commence by explaining the nature of this invention in the words of a small pamphlet, published by the pa- tentee, referring the reader to the accompanying plate in explanation, or those who are in Calcutta, to the model deposited in the rooms of the Asiatic Society. " The construction of Messrs. Jones & Co.'s wheels is upon a new principle, that of suspension. In the old wheels, those spokes, which are under the nave, support the weight ; in these it is jointly sustained by rods depending from the upper part of the felloe, as will be seen in the plate, fig. 1. The rod or spoke is made thick at the outer end, so as to be drawn firmly into a conical hole, bored from the outside of the felloe, and the nave depends from the rods, being sustained by nuts and screws within the cells, fig. 2. The advantage of this principle is, that it gives an elas- ticity to the lower part of the periphery of the wheel, which, while it diminishes the draught, is less wear to the road. An aperture, in which there is a thumbscrew, is made into the centre of the nave, where the oil cell is, and by which it is replenished, without taking the wheel off the axle. The cell contains enough oil to serve the wheel in work for five or six weeks. The Patent wrought-iron wheel s are made either cylindrical, conical, or dish- ing, and are either sold with the improved axles, or may be fitted to any others. Fig. 1 of the accompanying plate exhibits a perspective view of the wheels applied to a gun-carriage. Fig. 2 is an elevation of the same, with the ring of the nave open, to show the nuts of the suspension bars : their construction is more fully shewn in fig. 3 wherein a, b, are the front and back shields j c, a collet on the nose of the axle ; d, a screw with conical head, which passes through the collet, and fastens it to the axle ; e, a small screw through the side of d;f, a collar on the cap, which presses against a leather-washer, to prevent the oil escaping in front; gff, small bolts, which keep the shields in their places ; h, a thumb-screw, where oil is to be supplied ; jj, the nuts which are screwed on the end of the rods (or spokes) in the nave. The cap (in front of the nave) must be taken off, when the wheel is to be put upon the axle, in order to fasten the collet in its place, which is a substitute for a linch-pin. If the suspending rods of the wheels by any means become slack, each of the nuts must be screwed up (equally), which is done better by giving the head of the rod a blow with a hammer, and turning the nut at the same instant, taking care when done, that each nut presents one of its flat sides in front for the shield to press against, which will prevent the nuts unscrewing." I shall beg leave now to offer a few remarks on the appearance, durability, strength, efficiency, and comparative economy of the suspension wheels, and to pub- lish, for the satisfaction of those, who wisely wait for the actual trial of an inven- tion, before determining in its favor, the result of some experiments made by order of the Court of Directors, who have in consequence determined on a more extensive trial of the wheels by their ordnance department in India,