Roanoke
a city in Roanoke co., Va.; on the Roanoke river, and on the Norfolk and Western and Virginian railroads; 56 miles W. of Lynchburg. It is in a section rich in iron mining and farming interests. Here are a higb school, the Virginia College (women), improved sewer system, waterworks, street railroad and electric light plants, tels, and daily, weekly, and monthly periodicals. It has large machine shops, rolling mills, bottle works, tobacco factories, locomotive and car works, iron and steel works, canning factories, spoke factories, saw and planing mills, coffee and spice mills, and many smaller industries. Pow. (1910) 34,874; (1920) 50,842. improvement of the highways only began National and State banks, several hoin the 19th century. When diversities of level are necessary, road engineers fix the degree of inclination at the lowest possible point. Telford estimated the maximum inclination of a road to be 1 in 24, but, except in extreme cases, it is considered better that it should not exceed 1 in 50. The angle of repose, or maximum slope on which a carriage will stand, has been estimated at 1 in 40.
A properly constructed road, besides a foundation, consists of two layers, an upper and an under. After a good foun-