DRAINAGE OF THE ROAD, 273 



across and then lengthwise, covering the whole with not less 

 than two feet of the best material at hand. If a layer of two 

 or three inches even of coarse gravel can be put upon an earthen 

 road once a year, it is a great improvement. 



Sidewalks should be from four to six feet wide, sloping in- 

 wards with a fall of two inches, the top to the depth of six inches 

 being fine and clean gravel, with a very porous substratum like 

 that of drive-way ; there being no danger in this case of forcing 

 up the large pebbles from beneath. 



The natural place for sidewalks in villages, and wherever they 

 extend into the country with light road cutting and filling, is by 

 the side of the fences ; but otherwise thay must be at the side 

 of the drive, and form a part of the road-bed, to lessen the ex- 

 pense of construction. In either case the walk should be a little 

 higher than the centre of the drive ; and in the latter, on gravel 

 roads, the best way is to give an extra width of road-bed, and 

 lay planks lengthwise upon 4" X 6" cross pieces, thus giving free 

 passage for the surface water at every point. But away from 

 the vicinity of villages the expense of sidewalks will usually be 

 saved, and the footman will take the drive-way. 



Embankments must have a greater width where railings are 

 needed, and these should always be placed where the fill exceeds 

 three feet. The clear width between the railings should not be 

 less than twenty-two feet, and three to five more in case a side- 

 walk is required, and two feet additional on each side for the 

 strength of the railings. The following cross-section sliows the 

 plan upon embankments, with a plank walk on one side, and 

 railings, at minimum width: — 



Drainage. 

 This part of road-building is really the most important of all. 

 A thoroughly underdrained road-surface will not be seriously 

 affected by the heavings of frost, will dry up speedily after rains, 

 and will be passable at all seasons of the year by the average 

 loads, though the materials composing it may be of an inferior 



35* 



