File:City roads and pavements suited to cities of moderate size. (1902) (14801277553).jpg

Identifier: cityroadspavemen00juds (find matches)
Title: City roads and pavements suited to cities of moderate size.
Year: 1902 (1900s)
Authors: Judson, William Pierson, 1849-1925
Subjects: Streets Pavements Roads
Publisher: New York : The Engineering news publishing company
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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ds of broken stone, andthe use of this material was not peculiar to Macadamsmethod; but he was the first to establish rules of con-struction which were generally accepted, and underthem were built 25,000 miles of road which formed anetwork all over England; so that his name has cometo be associated with broken stone as a road material,although Telford, who came twenty-five years later,used the same material but in a different manner. InMacadams talk to committees of Parliament and to hisworkmen, he always enforced the idea that the wholesecret of making a good road was to keep its earth-beddry; that the ground was the real road and must bearthe weight of the stones, as well as of the traffic, andthat the subsoil, however bad, would carry any weightif made dry by drainage and kept dry by an imperviouscovering. In this requirement Telford and all skillful roadmakers fully agree. This dry roadbed. Macadam covered with a layer ofroad metal of a finished thickness of five to ten inches 150
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be M C 3 o « •^ ^ 3 « _. *^ 1- - O X J i^HliilHBHHHaBaB^ CITY ROADS AND PAVEMENTS. (varying with the weight of traffic), composed of smallangular fragments of the hardest and toughest rock,broken to a uniform size, as nearly as possible to oneand one-half inch cubes, or six ounces each in weight.No dimension larger than two inches was allowed, andany piece too large for a workman to put in his mouthwas to be broken again. In the matter of Telfords foundation for a brokenstone road and Macadams omission of it, there arewide differences of opinion and of practice: Frenchand English engineers generally omitting the telfordfoundation and many American engineers seeming totend toward the same practice, or to limiting the use oftelford foundations to those portions of roads where theearth subgrade is not firm. The latter practice is best because where the sub-grade is firm, the telford base serves as an anvil uponwhich the shocks of traffic break the fragments whichform the surface. Whe

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