Page:Remarks on the Present System of Road Making (1823).djvu/198

 would not have been so much felt, had it been spread regularly over the whole length (see No. 5, in the plan.)

The disadvantages of a flat road again are, that even if it is supposed to continue so, it is bad in principle, by doing away the tendency which a road ought to have, in every direction, to clear itself of water; but as the greatest wear will always be in the middle of the road, a level or flat road will very soon be concave; the middle of the road then becomes the watercourse, and the consequence, if the road is upon level ground, is, that the water and mud lie upon it, and injure the foundation and materials; or, if otherwise, that the stones or materials of the road are washed bare, and liable to be loosened and thrown up by the wheels coming into contact with their exposed angular surfaces. Many of the roads in the country afford examples of this, particularly after heavy rains, and if the country is at all hilly.

The best form for a road, in order to avoid those evils, is,—in my opinion, to form it, and to keep it with just a sufficient rise towards the middle, to incline the water towards the sides; and in place of making the whole width the section of one curve, to form it by two straight lines, forming inclined planes, and joined by a curve towards the middle. I have prepared a section of a road in the manner I have described (No. 4.) and as the lines, excepting at the centre, are straight, the section may be made to suit almost any greater or less width, by merely extending them. The section is taken nearly from a part of a road made under my direction in the country. The dotted line drawn upon it shows the form I alluded to when speaking of the circular road that ought to be avoided. I have seen ridges formed in what I thought well formed land, much after what I would recommend for the form of a road. The object of