ill-prepared materials, the wheel piles them up one upon another, and that forms a very narrow rut, which just holds the wheel; but a rut made by wear upon a smooth surface, is rather a concave hollow than a rut, and will present no difficulty to a carriage in travelling, and that is the difference between a rut produced by wear in a very well-made road, and that produced by displacing the materials.
Is there not much injury done to the roads by the heavy weights both of coaches and waggons?—I am not disposed to think that upon a well-made road the weight of coaches is material, or that it would be judicious to make any legal provisions affecting that subject. In regard to waggons, I conceive that the loads carried upon wheels of the description encouraged by recent acts of parliament, whatever their weight, would be very little injurious to well-made roads. I think a waggon wheel of six inches in breadth, if standing fairly on the road with any weight whatever, would do very little material injury to a road well made, and perfectly smooth. The injury done to roads is by these immense weights striking against materials, and in the present mode of shaping the wheels they drive the materials before them, instead of passing over them, because I think if a carriage passes fairly over a smooth surface, that cannot hurt the road, but must rather be an advantage to it, upon the principle of the roller.
Are you not of opinion that the immense weights carried by the broad-wheeled waggons, even by their perpendicular pressure, do injury by crushing the materials?—On a new-made road the crush would do mischief, but on a consolidated old road the mere perpendicular pressure does not do any. But there is a great deal of injury done by the conical form of the broad wheels, which operate like sledging instead of turning fairly. There is a sixteen-inch wheel waggon which comes out of Bristol, that does more injury to our roads than all the travelling of the day besides.
Are you of opinion that any benefit arises from those broad-
