CONSTRUCTION OF ROADS. 



131 



Fig. 5. 



The old method was to croivn the roadway ; that is, to give it a 

 curved section, as shown in Fig. 5, but 

 this is found to be objectionable from 

 the fact that vehicles, in order to avoid 

 the sloping sides, keep in the middle of 

 the road, and cut it rapidly into ruts ; 

 it is preferred, therefore, to make the 



cross section with two slopes meeting in the middle, as in Fig. 6, the 

 point being slightly rounded off. In 

 this way the same difference of level be- a m 



tween the center and sides may be made, \/~^^— — ' \V — 



and the inclination near the side will not Fig. 6. 



be as great as by the old method.* 



The general cross section is shown by these figures. In Fig. 5 the 

 ditches or gutters are between the road and the foot paths. There 

 are two objections to this ; if the ditch is at all deep, there is some 

 danger of overturning a carriage if the wheel is driven into it, and it 

 is difficult to cross from the foot walk. 



A better arrangement is shown in Fig. 6, where the ditches are on 

 the outside of the fence or hedge, and the water which falls upon the 

 surface of the road runs into them by drains passing under the foot 

 path. 



In a new country where much labor cannot be spent upon the roads 

 it is sufficient to dig two ditches, about eighteen feet apart, and throw 

 up the earth between them to make the road, taking care to cut off 

 the sod and grub up the bushes from the surface, before laying the 

 earth upon it, so that it may bind well, and not be in danger of slip- 

 ping into the ditch. 



When the road is higher than the land around it, there is no diffi- 

 culty in draining it, but when it is below the general level, more 

 provision must be made for carrying off the water ; the excavation must 

 be made of sufficient width to contain the road and its two ditches, as 

 shown in Fig. 7 ; and the road must not be made to serve the purpose 

 of a ditch itself, as is frequently the case — Fig. 8. 



Fig. 7. 



If the excavation is very deep, the road may be made rather more 

 narrow at that point. The bottom of the ditches should be at least two 

 feet below the roadway, may be lined with stone, if convenient, and 

 should be kept clean. 



Stiff clay soils that retain the water, require the most careful drain- 

 age ; gravel and sand are more easily kept in order, since the water 

 percolates freely through them. 



*-This slope should be about one fifth of an inch to the foot, 

 much greater. 



It is a mistake to make it 



