HIGHWAY CONSTRUCTION 61 



wagons in the same time, and that the cost of this handling is from 

 1 -V to 2V cents per cubic yard. 



Points to be Considered in Selecting a Road Machine. ID 

 the selection of a road machine the following points should be care- 

 fully considered: 



(1) Thoroughness and simplicity of its mechanical construction. 



(2) Material and workmanship used in its construction. 



(3) Ease of operation. 



(4) Lightness of draft. 



(5) Adaptability for doing general road-work, ditching, etc. 



(6) Safety to the operator. 



Care of Road Machines. The road machine when not in use 

 should be stored in a dry house and thoroughly cleaned, its blade 

 brushed clean from all accumulations of mud, wiped thoroughly dry, 

 and well covered with grease or crude oil. The axles, journals, and 

 wearing parts should be kept well oiled when in use, and an extra 

 blade should be kept on hand to avoid stopping the machine while 

 the dulled one is being sharpened. 



Surface Graders. The surface grader, Fig. 42, is used for re- 

 moving earth previously loosened by a plough. It is operated by 

 one horse. The load may be retained and carried a considerable 



Fig. 42. Surface Grader. 



distance, or it may be spread gradually as the operator desires. It 

 is also employed to level off and trim the surface after scrapers. 



The blade is of steel, }-inch thick, 15 inches wide, and 30 

 inches long. The beam and other parts are of oak and iron. 

 Weight about 60 Ib. 



