20 PBACTICAL FLORICULTUEE. 



double drains are required, I generally recommend the 

 following system, shown in figure 3. 



It will be seen by the first diagram that the bottom of 

 the ditch represented in the cut is an inclined plane, run- 

 ning downwards from one side of the walk toward the 

 opposite side to the drain, which I figure here simply as a 

 stone drain. The stoning is to be laid uprightly, and 

 never flat, on the hardened bottom of the ditch or dug- 



Fig. 3. SECTION OF BOAD WITH DOUBLE DRAINS. 



out trench ; if laid flat, the stones will never bind together, 

 but if upright, they will soon become tight by the intru- 

 sion of the gravel that has to be put on top of them. 



The depth of the trench depends very much on the 

 quality of the subsoil, and has to be regulated by it, and 

 so with the ditch for the drains. 



Such walks also depend very much on the quality of 

 the soil, and very often, indeed generally, on the facility 

 of procuring the materials. 



In some places I have seen walks and roads made by 

 simply scratching off three or four inches of light top soil, 

 beneath which was gravel several feet deep. Such a road 

 may be dry, but is very noisy, tiresome, and movable. 



In other instances I have seen walks made by opening 

 ditches over four feet deep, only for the sake of burying 

 rocks and saving the soil found in digging ; these form 

 very fine drains, and help to clear the land of boulders 

 and rocks, as is the case on top of Orange Mountain, N. J. 



The second diagram (fig. 3) shows the section of a walk or 

 drive requiring more drainage. The bottom between the 

 two drain ditches forms a curving line, on which, if well 

 placed, the stones will soon form an arch, and give the road 

 all the qualities required. 



