Southern good roads . s rather an expensive mattei, ami ludess .yoxi havee\ei.\ load analyzed you are not certain, and this would add 50 per cent to the cost nf your ma-lirial. Tar varies in at different gas-works,hence the futility of giving prescriptions of so muchtar lo so much pitch, which in another town, buyingtar from another gas-works, would cause failure. Butthe same thing applies to tar from any works; it dif-fers at the sanu^ gas-works at different seasons of theyear. The tar from one gas-works is quite different tothe tar from another w irks in the same town. A
Southern good roads . s rather an expensive mattei, ami ludess .yoxi havee\ei.\ load analyzed you are not certain, and this would add 50 per cent to the cost nf your ma-lirial. Tar varies in at different gas-works,hence the futility of giving prescriptions of so muchtar lo so much pitch, which in another town, buyingtar from another gas-works, would cause failure. Butthe same thing applies to tar from any works; it dif-fers at the sanu^ gas-works at different seasons of theyear. The tar from one gas-works is quite different tothe tar from another w irks in the same town. A dif-ferent method in carbonizing the coal, using a lowergrade of coal, and very often a change in the manage-mint. alters entirely the nature of the tar and i-endersit unsuitable for tar-macadam purposes. If such difficulties are met witli in England, must be encountered in the United States, nuistbe infinitely greater, since the illuminating gas tarwhich is produced heie is an infi-rior aitiide. owing to. The Macadam Road East of Statesville, N. C. the fact thai the coal IVom which the gas is made is iu-ferinr, Jl is heated to a ver.\- much higher tempera-ture, the gas of jioorer illinninating p iwei being sub-sequently carburreted ;ind enriched, the retorts inwhich it is produced the horizontal , a tar high in free carbon or soot, and it isoften mixed with water gas tar and other by-productsof less value. Recourse is now being had in England t 1 the addi-tion of native asphalt to the tar to improve its ([uali-ty, and this is also the ease in the United States, Insome recent interesting experiments in the Borough ofBronx broken stone surfaces cemented with tar andwith tar containing various percentages of asphalt residuals were constructed. After a period of only , the superiority of the work in which the bind-ing nmterial contained asphalt is already visible. In a recent paper before the Second Irish Road in Dubli
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Keywords: ., bookauthorvarnerhe, bookcentury1900, bookdecade1910, bookyear1910
