LAYING OUT ROADS, ETC. 37 



to the drains as will carry the water briskly along, 

 and prevent stagnation ; and where the soil is stiff, a 

 quicker descent may be given, if thought necessary. 

 All main drains should be made in the lowest 

 parts of the ground to be dried, and they should in- 

 crease in size, according to the quantity of water they 

 may have to contain. All sub-main drains should 

 be made in a position between the main drains and 

 the smaller ones ; and as they are intended to collect 

 the water from the smaller drains, and convey it to 

 the main ones, they should be of a convenient size 

 between the two. All open drains in a wood ought 

 to be examined and cleaned once in two years; 

 for if they are not attended to in this manner, they 

 are apt to choke by vegetable matter lodging in 

 them. 



SECTION VI. — LAYING OUT ROADS IN NEW 

 PLANTATIONS. 



In all plantations of any considerable extent, it is 

 absolutely necessary to have vacant tracts left 

 through them unplanted, in the form of roads ; and 

 in laying these off in a new plantation, care should 

 be taken to see that no part of the wood should be 

 above one hundred and fifty yards distant from 

 some one of such roads. The necessity of this pre- 

 caution will appear evident, when it is taken into 

 consideration that the trees, when grown to any 



