and important subject, with regard to the perfection of roads; they should in no instance be more than five feet in height above the centre of the road, and all trees which stand within twenty yards from the centre of it ought to be removed. I am sure that twenty per cent. of the expense of improving and repairing roads is incurred by the improper state of the fences and trees along the sides of it, on the sunny side more particularly; this must be evident to any person who will notice the state of a road which is much shaded by high fences and trees, compared to the other parts of the road which are exposed to the sun and air. My observations, with regard to fences and trees, apply when the road is on the same level as the adjacent fields; but in many cases, on the most frequented roads of England, more stuff has been removed from time to time than was put on; the surface of the road is consequently sunk into a trough or channel from three to six feet below the surface of the fields on each side; here all attempts at drainage, or even common repairs, seem to be quite out of the question; and by much the most judicious and economical mode will be to remove the whole road into the field which is on the sunny side of it. In cases where a road is made upon ground where there are many springs, it is absolutely necessary to make a number of under and cross drains to collect the water and conduct it into the aforesaid side-drains, which I have recommended to be made on the field side of the fences.
In constructing the bottom part of a road, (which would, of course, be made of an elliptical form) if it is upon clay, or other elastic substance, which would retain water, I would recommend to cover the whole bottom of the road with vegetable soil, in cases where the natural shape of the ground admits; I would not remove the original surface, and where there are inequalities I would fill them up with vege-
