76 ©rives an& TlUalfcs. 



material, will be necessary to fill up crevices, and to join the 

 whole together. This layer in its turn must be spread, 

 aud packed into the mass beneath, by ramming or rolling. 

 For surface covering, about three inches of coarse gravel 

 should be used, from which the larger stones and the finer 

 sediment have been removed, or can be raked off after- 

 wards. When this is raked uniformly over the surface and 

 rolled or beaten down, the main part of the road is finished. 

 The finish of the edge requires some skill and precision. As 

 a rule, the edges of walks and drives — that is, the grass 

 edge — should be finished before the top layer of gravel is 

 put on. These should be firmly and solidly made of tough 

 and even sods. The sodded edges on both sides of the walk 

 must be on the same level, no matter how different the 

 general surface of the lawn. 



A piece of board cut out as shown in Fig. 39, is used to 

 make the surface of the walk uniformly rounded and to 



mark its exact width. 



S y 5 fc~r^=~~" J ° " s==a * g5S ^ ^^ a By means of this board 



FIG 39.-QAUGE USED IN ROAD-MAKING. We CftI1 alSO ^^J fiud 



out whether the oppo- 

 site sides of the walk are on the same level, by placing a 

 common spirit level on the straight upper edge. Of course 

 this gauge must be equally wide at both ends and perfectly 

 straight. 



In different places the material obtainable differs great- 

 ly. In many stoneless countries, oyster shells, hard clay, 

 and other materials are used in road-making. Oyster shells 

 make good, dry, and solid walks for a garden, especially if 

 covered with a thin layer of fine pebbles. Small pebbles of 



