1 88 ENGINEERING FOR LAND DRAINAGE. 



condition would be secured, the question of how to 

 obtain good roads in the country would be answered. 

 Soil absorbs water easily, so that it is scarcely possible 

 to make a surface that will shed it all, especially in 

 climates where the surface is subject to periodic freez- 

 ing, thawing, and rainfall. Roads which are excellent 

 during the summer season when the road surface can 

 be kept intact, lose all semblance to their summer and 

 fall conditions during the winter and spring months, 

 mainly because the surface is not water-proof. 



2. Surface ditches at each side should be provided 

 and so graded that storm water from the road surface 

 will be removed quickly. 



3. In order that the travelled surface or road crust 

 may have a firm foundation at all seasons of the year, 

 underdrains should be laid on one or both sides of the 

 road-bed near its base, to prevent the saturation of the 

 subsoil beneath the road. 



These three elements are essential to every good 

 road which is constructed on loam or clay lands. A 

 thoroughly drained sub-grade must be provided if we 

 expect to maintain a good surface, whether it be of 

 earth or of some better material. The difference in the 

 practice of the English road-builders Macadam and 

 Telford gave rise to sharp discussions regarding the 

 proper foundation for stone roads. The former claimed 

 that the base should be formed of the larger size of 

 broken stone which were used in making the road 

 covering, while the latter held that the base should be 

 formed of large flat stones, upon which the broken stone 

 should be placed. With thorough sub-drainage there 

 is no cause for such discussions. It is only where such 



