CONSTRUCTION OF WALKS AND DRIVES 93 



coarse gravel screenings, say three inches thick, 

 which should be formed with the rake to a 

 curved surface or camber in cross-section. The 

 gravel may then be evenly distributed over 

 the surface to a depth of from two to three 

 inches, care being taken to keep the line of its 



Fig. 18. — Path foundation 



crown straight in the direction of the path's 

 length, but preserving the camber of the layer 

 beneath. After liberal watering the roller 

 should be put to work. The free use of water at 

 this stage is important to success, as it ensures 

 the subsequent consolidation of the gravel 

 and prevents it adhering to the roller. The 

 correct amount of water may be determined 

 by noting the action of the roller, which should 

 carry before it a wave of creamy liquid, a mix- 

 ture of water with the binding constituent of 

 the gravel. The roller should be a moderately 

 heavy one. After the path has been brought 

 to a fair surface it should be left unused for 

 at least twenty-four hours, and if no rain falls 



