EXECUTION OF SOME OF THE LANDSCAPE FEATURES 71 



either wade or go out of his way. With catch-basins placed 

 in the center of the blocks, or, if the blocks are long, at some 

 distance from the crossing, the intersections can be kept rela- 

 tively high and dry. Roadways are generally made crowning 

 in the center so that water runs to the sides, but frequently the 

 fall lengthwise of the roadway is less than it should be. City 

 engineers are usually inclined to make the grade along the 

 length of a street as nearly level as possible. Authorities who 

 have given the subject of roads considerable study recommend 

 a fall lengthwise of not less than one foot in one hundred and 

 twenty-five, nor more than six feet in one hundred. Such 

 grades are not always feasible, but a certain amount of varia- 



69. A common form of edge for walk or drive. 70. A better form. 



tion in level can usually be made in a residence street which 

 will make it much more pleasing in appearance, and have cer- 

 tain practical advantages in keeping the street dry. The water 

 is usually confined to the edge of the pavement by curbing, 

 which may rise anywhere from four to fourteen inches above 

 the surface. This causes all the water falling on the roadway 

 to seek the catch-basin and be wasted, excepting for its use in 

 flushing the sewer. If the curbing, which is really unnecessary 

 in most cases, were omitted, much of the surface water would 

 soak into the ground between the sidewalk and the pavement, 

 doing much good to trees, shrubs, and grass. The roots of the 

 trees naturally extend as far, or farther, than their branches, 

 and for their good the ground under the pavement and side- 

 walk should be supplied with a certain amount of moisture. 



''The arrangement made for the removal of surface water 

 from the street must also take care of the surplus water from 



