Road Drainage. 445 



The better the more level portions of the road are, where 

 heavy teaming is done, the more important it is to reduce 

 the grade to a low per cent, because it is important to be 

 able to go over any hill readily which can be approached 

 with the largest load the team is able to hnndle without in- 

 jury to itself. The great importance of this point will be 

 readily understood when it is stated that the steepest grade 

 admissible on an average macadam road is 10.5 per cent., 

 and on a dirt road in good condition 16 per cent. But 

 as these grades will tax the team to its utmost the hills 

 should not be permitted to rise if practicable faster than 

 4 feet in 100 feet for the ordinary macadam and 6.2 feet 

 in 100 feet for the earth road in good condition. 



In thinly settled sections people must be content to im- 

 prove the roads gradually, but if the end finally to bo 

 reached is kept in mind all the time it will usually be pos- 

 sible to make each year's work count as permanent im- 

 provement and avoid tearing down one year the work of 

 the years preceding. 



EOAD DRAINAGE. 



The keeping of the road dry, both above and Lelow. is 

 the most fundamental necessity of a good permanent high- 

 way. Fill any soil, however hard and firm, completely 

 with water, and a child walking over it will mire ; and to 

 completely drain and dry any soft and marshy place will 

 leave it so that heavy loads may be moved across it readily 

 and safely. Drainage is one of the first requisites of a 

 good road. 



In some places only surface drainage requires attention. 

 Where the surface is more or less rolling and underlaid 

 with coarse porous materials, so that standing water in 

 the ground does not occur within 10 to 20 feet of the sur- 

 face, under drainage will not be necessary; but wherever 

 the adjacent fields would be improved by drainage, wher- 

 ever the ground is springy, and wherever the ground wn 



