Salt Lake Times | 1892-04-25 | Page 4 | Macadam and Telford Roads

Macadam and Telford Roads. Paving and Municipal Engineering. The two principal systems of artificial road covering are the Telford system aud that of macadam, or macadamizing. In the former the road bottom isjflrst dug down a few inches and a foundation is made of unbroken 6tone, varying in height from six to eight inches. These are set on edge and tightly wedged in place with small stones. Over this foundation is spread from four to eight inches of finely-broken finely-broken stone, none being used which wiil not" pass through a ring two and one-half inches in diameter. The convexity of the road-bed is given to it partially by the form of the earthy bed and partially by making tho covering cov-ering of broken stone, thicker at the center of thfr road than at Its edges. Macadam's sys-: sys-: . differs from this in that he would use no large stones in the bottom. He makes the coveriuff entirely of stone broken until the largest do not exceed six ounces in weight. There being no foundation but that of the natural soO, this system requires a coating of stone from seven to ten inches in thickness. This is applied in layers of three inches at a time, each layer being left until partially consolidated con-solidated before another ts added. Macadam claims that the whole science of artificial road-making consists in making a solid, drv path on the natural soil, and then keeping it dry by a durable waterproof coating; also that tho weight must be borne by the native soil, not by the covering.