44 STATE BOARD OF AGRICULTURE. 



force required to climb it will be five one-hundredths or one-twentieth 

 of the gross load added to the force required to haul the same load 

 along a level road having the same kind of surface as the road on the 

 hill. In other words, it would require just double the power to pull 

 the load up the hill as it did on the level. If the hill were to rise ten 

 feet to the hundred the extra force required in climbing it would be 

 equal to one-tenth of the gross load and so on. 



Inasmuch as a horse can exert fully double his ordinary working 

 strength for a short time, it is apparent that no road should have grades 

 that will require much more than double the force to climb than would 

 be required to draw the same load along level roads having the same 

 kind of surface. Thus a good earth road will not be appreciably 

 improved by reducing the grades to less than five per cent unless they 

 cover a considerable portion of the length of the road, while the best 

 macadam and gravel roads will not be ideally perfect unless the grades 

 are reduced to at least three per cent and, in extreme cases, to as low 

 as two per cent. 



Width and Shape. — Some country roads are too wide and some are too 

 narrow. From eighteen to twenty-four feet between the side ditches are 

 economical and practical widths for country roads. Each township 

 should classify its roads and adopt that particular width for each road 

 between these limits that is best suited to accommodate the travel it must 

 sustain. When the width of a given road is decided upon it should be 

 placed upon the plans and not varied from in the. future. 



The shape of a road must depend upon several things, but primarily 

 on the kind of soil it is built upon for that will necessarily fix the size, 

 shape and location of the drains. The road bed proper should have a 

 crown of from one-half inch to three-fourths of an inch for each foot of 

 width. This detail will also be shown upon the plan. 



CLAY ROADS. 



Clay and all classes of wet roads need thorough draining. Where 

 there is much surface water large open ditches must be provided. It 

 is important that these ditches have sufficient capacity to handle all 

 ordinary storms without flooding the road. They should have contin- 

 uous grades and free outlets in the natural water courses intersecting 

 the roads. It may be necessary to improve these water courses for 

 some distance outside the road allowance to prevent back water. When 

 necessary this requirement should not be neglected. 



Such ditches should be located along the side of the road from which 

 the most water comes so as to prevent as much water as possible from 

 soaking into the road bed. Large open ditches may be placed between 

 the regular gutters and the fence line, with occasional openings through 

 the shoul'ders between the gutters and the main ditches. When large 

 deep ditches are located alongside the road bed they should be protected 

 by suitable guard rails. 



Tile Drains. — All springy places and most clay roads will be imi)roved 

 by underdrains. To be of the most value their trenches should be filled 

 with cinders, coarse gravel or broken stone up to the road surface, 

 otherwise the road becomes puddled on the surface and prevents a 

 great deal of water from entering the drains. Two lines of tiles from 



