226 BOARD OF AGRICULTURE. [Pub. Doc. 



roads. It is not too much to say that, for adding depth 

 and security to the best road work, .sands and gravels 

 devoid of all suspicion of loam or clay-producing material 

 are fully equal to any possible quality of stone, when 

 bedded below all chance of wheel-friction. This value 

 of sand and gravel for the best roads over clay, brings them 

 well within the line of profitable railway commodities. 



The reason why cobble-stone and granite-block pavements 

 so frequently settle out of shape and make a rough, jolting 

 road, is because the sand used is dirty, rarely or never com- 

 pacted by trampling or puddling, and in cities is often dug 

 deeply in holes and ditches for pipe repairs, etc., just before 

 and while the pavement is being laid or rclaid. In such 

 cases cement finds opportunities that would not appear if the 

 sand were faithfully and intelligently treated. 



Beginners in road making may need to be told that fresh 

 deposits of sand shrink in settlement, and how the shrinkage 

 can be hastened by rains, artificial waterings and the tramp- 

 ling of horses and cart wheels in a concave road-bed. A boy 

 and one horse will do the work of many paving rammers. 

 The firmness of sand under water is well shown by the fine 

 wheeling on some sandy beaches while the tide is out. 



Where neither sand, gravel or coal ashes is to be had, and 

 a solid road of broken stone is desired upon a clay subsoil, 

 the drainage of the clay must be thorough, and the most 

 scrupulous pains taken to have the stone fine enough to fill 

 its own crevices perfectly, and resist the ingress of the 

 insinuating clay. Not only the bottom of the stone-road 

 body,, but the whole substance and texture of the crushed- 

 stone structure, must be impermeable to clay or mud in any 

 form, and the water of rains also, that might else wash sur- 

 face filth and clay silt among the broken stone. The per- 

 manence of the road depends on absolute faithfulness in these 

 particulars. In this light the value of the bottom filling of 

 sand will be seen, because is is so much easier than stone to 

 handle, and in its place even more effective. 



It is impossible to pass, in this connection, the modern 

 doctrine of painstaking " porosity" in stone-road structure, 

 without condemning it as a ruinous fallacy, chargeable with 

 ninety-nine one-hundredths of our costly failures in pro- 



