fiOADS MIS 



must decrease. According to CI il U-spii*. if a horse can 



pull on a level 1,000 pounds; on a rise of 1 foot in 100, 



or 1 pel cent, be can pull 900 pound- : on a rise of 1 foot 



. or -J per cent, he can pull 810 pounds; on i rise 



of 1 foot iii '.**», of ! pet cent, he can pull 540 pounds: 



and on i rise of 1 foot in i<>, or 10 pei cent, he can pull 



onlv '?."><> pounds. These figures show how important it 



oid \<tv steep grad 



(2) Good drainage ia equally aa important as good 



grades. Wei ipota in the road, if neglected, boob become 



mudholes which prevent the hauling of anything but 



li^ht loads. All wet portions of the rood should be 

 onderdrained, just as wet fields are drained, the drains 



Fio. 24.— Section of macadam road with dirt tracks on either Bide. 

 Shown ditches for surface drainage. (After a drawing in Yearbook, 

 U. 8. Dept. Agr., 1804, page 602.) 



constructed in the same way. To carry o(T the 



surface drainage, Open ditches on either side of th< 



should be constructed. The drainage ditches must, "f 



course, have nunc outlet into some creek or gully. A 



feu dollars carefully expended in draining i road may 

 i bangs an almost impassable road into a fairly good one. 

 Unless properly drained no road can he kept in good 



condition. 



(3) Thi >f the road should he wide enough 



to accommodate all travel, and the center ihould be 

 higher khan the aides. Fig, ?! shows how the surface 



of a well constructed road [| huilt up. The ceir 



oad ihould be just high enough above the d 



