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Show DRAINAGE NECESSARY TO , PRESERVE ROAD FOUNDATIONS' Properljr Constructed Macadam liomis Are Supplied With d Drain to Carry Off Surplus Wuter Some Excellent I'lunA. (By a. n. Fi.rrrcHKu Water should never be permitted to remain under a macadam road. It softens the foundation so that the broken bro-ken stone Is forced down Into It by the wheels of vehicles, thus canning ruts to develop In the macadam. In free ting It expands and heaven'' the broken stone, destroying the bond ami causing ttip larger fragments of stone to rise to the surface. As a result the ninteri.il In the suM-.rade Is forced up Into the Interstices, and In the spring the marndum will M found to be rough, irregular In shape, and weakened. weak-ened. There are several ways of removing re-moving the subsurface water, at least In part. Sometime If the grade Is raised In wet places the trouble will be lessened, particularly If porous materials are used. Side drains may he constructed In the cuts on each side of the road. Just outside of the limits of the macadam. These drains consist of narrow trenches, trench-es, filled with broken stone or small gravel stones, with a pipe five or six Inches In diameter near the bottom. outlets. These trenches should also be filled with stones. Such a drain Is usually effective anil ordinarily costs , less than two side drains. I Another way of multiplying In part the effect of the subsurface water Is to construct a foundation of telford. i Formerly, nearly all macadam roads were built with a telford base, regardless re-gardless of any consideration of the requirements of traffic, It Is now generally recognized that, except In unusual cases whtre the suhsull Is full of water which cannot be drained out, the telford base Is unnecessary except for purposes of Ftihdrnlnnge. A satisfactory telford foundation may be made by plating vertically on a layer of gravel two or more Inches In depth, stones of fairly uniform size, not exceeding ten Inches In width, six inches In depth, and varying In length! from six to twenty Inches. The stones sliouid be set on their broadest edges, lengthwise across the road, and wedged rUldly Into positl:)n by driving smaller stones Into the Interstices with niaulh. Projecting p ints should . w -in), 1 ' ii ii TTTiTTf n II i .' S; r ", o -, . . j . f f o , i x r y j f i m.'o--'-'Al H- iiTiVv'O '.: iX. S Ii Uil"" I j I I !! H- IS O" -I II I . u . o t t-'r--i- Joiii 61 DC DRAIN , Bil'JO CM 1ft. Typical Cross Section of Macadam Reads. The pipe Is laid with open Joints, true to grade, an,t Is curried to a proper outlet. Sometimes the pipe is omitted omit-ted and the entiro trench Is lilled with stones. In which cue It Is called a blind drnln. Such drains serve to cut off the btiiiKiirfaco water before It can T under the macadam. The tubgrndo may be excavated to the width of the macadam m as to be fix to eight Inches deep at the edges, and twelve to eighteen Inches deep nt the center. The surface will then have the shape of an extremely flattened flat-tened letter V. The bottom should be fairly true to grade, fo as to permit the water to flow readl.y. This excavation exca-vation Is filled with stones varying In size from small pebbles to boulders eight or ten Inches In diameter, th largest being placed at the bottom. These stones need not be placed with pceial care, but the condition of the ; mass should be such ns to permit consolidation con-solidation with a roller. To dispose of the water collected by a drain of this kind, narrow trenches should be cut to the sides so as to coniuct with op:n be broken off with stoup hammers. tle press ions filled with chips, and the telford rolled with a steam roller until It Is true to the de; lied cross sec-lion. sec-lion. Where tho foundation of the road wouid otherwise lie very bad, and no gravel or otlir like material la readily obttiinnb e. rr where an unusually un-usually substantial road Is required to meet the demands of I raffle, this form of construction is recommended. I'nder irdlnary conditions It Is much too expensive. It has been said, nnd there is some supporting evidence. I that a rigid and unyielding telford has has the efTeet of an anvil, und that ti e macadam, under the pound of trnflic, wears mere rapidly than In the ordinary bn ken stone road. Several ether d vices urn sometimes some-times employed to take care of the Mibsnrface. water, such as the center box drain, built of k'iiIi of (tone, mid side drains, with plank boxes In lieu of drain tile. I'suallv these t;re either too e nlve or too unstable a nature to be rcco: imemV.t, |