20 BULLETIN 463, U. S. DEPARTMENT OF AGRICULTURE. 



CLEARING. 



After the work has been staked out the right of way should be 

 cleared of all trees, stumps, brush, fences, etc., which occur within 

 the lines of the work. Trees and stumps should be grubbed out 

 or cut off at least 18 inches below the finished surface of the road- 

 bed over them, and no parts of trees, stumps, or other perishable 

 matter should be left in areas to be covered by embankments. 

 Sightly trees that would not interfere with the work or obstruct the 

 road in any way should be trimmed to a neat contour and left to 

 afford shade. 



CONSTRUCTING CULVERTS, DRAINS, ETC. 



All drainage structures extending under the surface of the road 

 should be completed," and the necessary backfills made over them 

 before the work of grading is begun. There are two reasons for this. 

 One is that usually less excavation will be required for such structures 

 before the grading is completed than after, and the other that it is 

 desirable to give the backfills as much time as possible to settle before 

 the grading is completed, so as to avoid irregular settlement later. 



The conditions under which culverts and drains are constructed 

 vary to such a great extent that no attempt will be made here to 

 discuss the detailed methods of construction. 



The grading of an earth road includes all excavating, hauling, 

 and filling necessary in constructing the roadbed, slopes, side ditches, 

 etc., and usually is by far the largest item of work connected with 

 earth-road construction. The most economical methods and ma- 

 chinery to employ in grading a particular road depend on the charac- 

 ter and amount of the work to be done. Where, for example, the 

 grade and cross section of the road follow closely the original ground 

 surface most of the necessary grading usually may be done with a 

 grading machine such as is illustrated in figure 11. In the case of 

 embankments, built up with material from borrow pits along the 

 sides of the road, an elevating grader (fig. 14) frequently may be used 

 to advantage. If material must be moved longitudinally along the 

 road from cuts to fills in order to bring the surface of the road to the 

 required grade, the work usually must be done either with scrapers 

 (figs. 16 and 17) or dump wagons (fig. 18). Where a considerable 

 volume of material is to be excavated in a relatively short distance a 

 small steam shovel (fig. 19) with dump-wagon equipment sometimes 

 may be employed economically. Each of these methods may best be 

 described separately. 



