Page:Report from the Select Committee on Steam Carriages.pdf/135



Mr. Richard Trevithick. 12 August, 1831. the hind wheels should go in different tracks?—Yes; the one produces a burr, and the other smooths it down.

Will the Carriage run so easy?—No; it would for one turn; but in the course of time, going every day backwards and forwards, the work will be done easier.

You think the tire may be extended to almost any width; what is the width which you think a Steam Engine travelling rapidly ought to have?—It depends upon the weight they have to carry; but if you draw a conclusion from the Coaches carrying four tons on two-inch wheels, you might, with a great deal of convenience to the Engine, make them six; but a six-inch wheel would not break one-tenth part of the stones which a two-inch would.

You see no objection to a Steam Carriage, intended to travel fast with passengers, which may weigh as much as a coach and four with its horses, having a six-inch tire?—No; I know it is condemned by people in general; but I have never beard, nor have I seen, any reason for its being condemned.

The wheels being wide and being cylindrical, with their axle horizontal, supposing you were to double the diameter, or to increase the diameter considerably of a wheel six inches wide, would it go more easily for the road?—It would go easier for the machine; but then there must be a wheel of double the width, and that would be loading the machine in going up hill with an unnecessary weight; but that would ease the road; it will have a longer bearing on the ground; there would not be so quick a circle.

With respect to the road, there would be a considerable advantage?—Yes, for it is a larger arch.

With respect to the Engine, would there be any other disadvantage but the additional weight?—No; I do not know any material objection except that, and that would throw the Engine very high; it would be top heavy. I do not think it would be convenient to make wheels above six feet.

Can you state the weight of your Engine as compared with the weight of the present Engine?—I will furnish an answer to that question.