The Construction and Maintenance of Roads. 



By ALFRED J. BURROWS, Pluckley,' Kent. 



{Continued from fcirje, 555.) 



The accompanying diagram (fig. 1) of a road section is given as an 

 illustration of the method of construction recommended in a former 

 article. A B represents the surface of such a road, 15 ft. in width 

 and having a convexity of 1 in 30, or a fall of 3 in. from the centre 

 to the sides. Its entire depth from A to G is 18 in., and the bed 

 upon which it is laid has the same convexity, to enable water to 

 escape more readily to the side drains. G- H is a bottom of flat 

 stones about 7 in. in thickness, closely packed in the form of a pave- 



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Fig. 1. 

 ment, and well rammed down upon the soil. E F is a layer of good 

 road metal, broken into 2 in. cubes, and laid on to a thickness of 6 or 

 7 in., and thoroughly consolidated by rolling, ramming, or carting over 

 the surface with broad wheels. C D is a coating of finely broken 

 stone or gravel of the best quality, 4 or 5 in. in thickness, covered 

 with fine chippings from the quarry, or with sand, and then well 

 watered and rolled down. 



Where the upper coating consists of angular or broken stone it 

 cannot be too carefully sifted or freed from dirt, as the angularities 

 will produce interlocking and complete binding ; but where it consists 

 largely of smooth or rounded pebbles it is a mistake to divest them 

 of all earthy matter, as in such a case they will bind only when they 

 become crushed, by which time the surface of the road is materially 

 weakened. 



It should never be forgotten in road-making that the larger the 

 amount of earthy matter embedded in it, particularly when this is of 

 a clayey nature, the greater the loosening effects of frosts. 



