MOST IMPORTANT REQUISITE. 285 



Chaeacteristics of a Good Road. 

 The characteristics of a good road are hardness and eveness of 

 surface, with a degree of smoothness which will enable carriages to 

 move with the greatest ease, while affording a sure foothold for 

 horses ; the hardness being sufficient to resist the pressure from 

 loaded wheels and the hoofs of animals going over it, but not so 

 great as to prevent entirely an elastic yielding under moving 

 loads. The art of road-making consists, in a great measure, in 

 applying the best means to secure these qualities, and in such a 

 manner as to insure durability against the wear of use and the 

 action of the elements. 



Drainage. 



The requisite foremost in importance, attention to which can- 

 not be too urgently insisted upon, in the construction or im- 

 provement of roads, is thorough drainage ; for without this a 

 durable or even a temporarily good structure is hardly possible. 

 Neglect in this particular is one of the main faults of our method 

 of treating roads. 



Provision must be made not only for the removal of surface 

 water, but of all excess of moisture from the substratum below 

 the roadway. Under-drains should be laid wherever the soil is 

 not sufficiently porous for self-drainage, and the water tables and 

 side ditches should be so arranged as to carry all surface water 

 quickly away. 



The under-drains should be put down in the same manner as 

 for agricultural purposes — say about three feet below the sur- 

 face, and from eighteen to not more than forty feet apart, accord- 

 ing to the character of the soil and amount of water retained 

 by it. Generally, these drains would be arranged longitudinally 

 with the road, but in some cases they may be put across it, in 

 the form of a flat Y, the angular point highest, or up the in- 

 cline on descending grades. This work must be executed with 

 judgment and careful attention to details, to be effective and to 

 save unnecessary expense. 



The side channels, or water tables, for receiving the water 

 from the road-surface, should have a fall of as much as 1 in 

 30 ; but the inclination should not be so great as to produce 

 violent currents, and at short distances means should be pro- 



