Page:Report from the Select Committee on Steam Carriages.pdf/133



Mr. Richard Trevithick. 12 August, 1831. crushed, for the stone does not bear strongly enough together to resist it.

For this reason, the operation of horses' shoes must be much more injurious than that of broad wheels?—Yes; they are more likely to break the hard stones than a dead weight. I think the horses' feet much more likely.

There are certain states of the roads in which the widths of the wheel would occasion your losing power, are there not?—No. I think not. I have heard that mentioned, but I think is not so.

Is there any slipping or sliding in the wheel of the Steam Carriage?—When the trial for the premium given on the Manchester Railway was decided, the Engines ran for a certain time, and the strokes were counted, and the distance was measured, and there were remarks made upon that day's performance, they found, by measuring the periphery of the wheel, the number of the strokes made, and the distance run, that there was not the least variation whatever; they could find no difference.

Was not that on a Railroad?—Yes.

The cylindrical wheel, with the horizontal axle, is the best for the road?—Yes.

Is there not much less likelihood to slip on a common road, than on an iron Railroad?—Yes.

Suppose there are sharp ascents upon a common road, how would that apply?—There is no ascent that any common carriages go over, where the Steam Carriage will not go down hill with one wheel chained; no road in the neighbourhood of London that they would not run down with one wheel chained; that is, only one quarter part of the weight of the Carriage, if the wheel is chained, if you are drawing up hill with two or four wheels driven by an Engine, by their all turning round, they are as likely to go up hill. One wheel ought to put it up hill. It will go up a hill of double that ascent without slipping.

Will the increasing breadth of the wheel render slipping in ascending a hill more or less likely to take place?—I rather think that will increase the friction, because that does not tend to make a rut. In making