Page:Remarks on the Present System of Road Making (1823).djvu/196

 the pit, excepting the upper foot, or 18 inches or so, which is screened; but if whin or other stone is to be used, the size of the pieces into which it is broken should decrease as we approach the surface, the superficial coating not exceeding a cube from 1 inch to 1-1/2 inch. If the foundation is bad, breaking the bottom stone into small pieces is expensive and injurious, upon the principle I have above described, and also for the same reason that an arch formed of whole bricks or of deep stones is to be preferred to one of the same materials broken into smaller pieces, for in some counties the materials will admit of the foundation of the road being considered as of the nature of a flat arch, as well as of being supported by the strata directly under it: but the error in laying the stone in large pieces upon the surface is more common and more injurious. In all cases, whether the material is gravel or hard stone, the interstices between the pieces should be filled up solid with smaller pieces, and the finishing made by a thin covering of very small pieces, or road-sand or rubbish, for those interstices must be filled up before the road becomes solid, either in this way or by a portion of the materials of the road being ground down, which last mode occasions a waste of the material, and keeps the road unnecessarily heavy and loose. This observation applies to the repairing as well as the original making of roads, and the effect of this covering, or as it is called in the country, blinding the loose stones, is so evident, that I have often wondered to see so little attention paid to it. If the material is soft, as some lime-stone, this is less necessary, and the quantity ought never to be more than is just sufficient for the purpose I have described. In the original making or effectually repairing of a road, it is, I think, best that the whole of the proposed thickness be laid on at once, for the sake of the road as well as of the tra