The Montgomery advertiser., 1906-11-05
mERT FOR COUNTY ROADS; ADVANTAGES IT PRESENTS

tuaily be forced into the side ditches.
 Method. of Construction.
 MT. M C. Eldridge, Chief of Records, United States Office of Public Roads, says: "The road bed should be shap ed with road machine before the ma crown of from s-s T to fi-s inch to o''f"' the foot, from the center to the sides. The foundation should then be rolled, the material for the first course spread in in the usual manner. The spreading of the material can be accomplished by the use of road machine. provid- total depth may vary from four inches to nine inches at the center as soil ana trafhf may require, and gradually mon asd n thsknsfs fsatSeT tn what edrs s the most approved method is followed. shoulders should be provided to hold the material in place. The material depth from the center to sides" The built as follows: The chert for the % fosndafions were first aaiI obtained s0iS bS rolling. First course of stone tcherD put on four inches in thickness. The rolling was from the edges toward the center. Second course of finer mater ial was put on two inches in thick ness. The last course being fine | rolled until the whole was competed, having a thickness of six inches at the center and four inches at the. sides: The cost of the. chert per cubic yard The average cost of grading. Lprepar- ing foundations. rolling. unloading, hfagling stone sso eo road and laying com
 In Jefferson County there are prob ably 250 miles of chert roads with widths varying from sixteen to twen- Land Company. cherted about mile of road system. and the road was ex- tended in both. directions. using the probably as heavy traffic over this road as any in the county. and 1t has been in constant use for nineteen years with little or no repairs, the read rSs
 Jefferson County Roads were origin
 ally built by placing upon the sub sub through d 2-inch ring and spread nine inches thick in center and six inches in thickness at the edges; over this was spread layer of chert from three der traffic soon formed smooth ce- | mented roadway. The county has never owned a roller, and none has
 been employed on any ar of ,s the roads The ne | slag upon the sub-grade, which Is | crowned six inches at center, and from
 twelve to eighteen inches in width,
 the slag being put on @ six ,la,t inches soi,n in
 and one-half inches in thickness at sides. The city of Birmingham has
 about forty miles of chert streets or roads. Some of these streets were
 built by simply forming the natural
 material of the street and compacting
 it with a steam roller. The roller used
 by the city weighs fifteen tons, weight on each 20-inch wheel, six feet in diam | eter. being five tons. On all cherl '1
 streets, a foundation course of slag Is
 placed on a well-compacted sub grade The slag delivered and rolled. costs l so cents per cubic yard, put on four l inches in thickness or cents per
 square yard. The chert costs from '. | in place and rolled. It is spread on an 1 average to a thickness of five inches ] in certer and decreased to three inches | at sides and rolled until smooth and
 compact The center rise or crown where chcrt is used a. Birmingham Is l about one-thirtieth of the width of the | street. measured from outside of gut | ters Cutters are three feet wid 2 | measured from outside edge of curb l On grades a little in excess ot one | thirtieth of street is used to determine | center rise. .+ | The chert now being used at Bir-
 mineham comes from Banks. nea' | Fassemr. It costs about so cents p"i l ine freight charge of 2 cents per ton l and weiphs about 9.S00 pounds per cubic vard on cars.
 | Tn Jefferson County, where slag Is not available. the foundation course Is made of the harder and cOurser porti | of the chcrt used and placed from l to Incho thick: tho ton course heins 2 ! inc same as where slag is employed foi 1 foundation.