252 ON THE DRAINING OF PLANTATIONS, 



the pipes, while destructive to the roots of trees, entails considerable 

 expense, because, after the roots have once reached the pipes, these 

 operations have to be often repeated. "We have seen pipes, tiles, 

 and stone drains so Ghoked with tree roots, that it was impossible 

 to extract the mass without breaking the pipes. In such cases, the 

 drains had been made after the trees had arrived at considerable 

 size, but the result would be equally bad in young plantations, 

 although the time of destruction might be postponed. Elm, ash, 

 and poplar are most destructive to covered drains, as they choke 

 them with their roots in a short time, even if growing at some 

 distance. Larch, spruce, and other surface rooting trees are not so 

 liable to cause injury in this way, and covered drains may therefore 

 be adopted more effectively in fir plantations, than among hardwood 

 . for the removal of bottom Avater. 



The liability to injury of covered drains in hardwood plantations is 

 much to be regretted, because they can be made with equal con- 

 venience to any depth, and but for this objection, would not only 

 dry the ground to a greater depth, but would save the trouble and 

 expense of clearing open drains, which often get filled with soil, 

 -. branches, herbage, &c. It has often been observed that 

 drains which had not enough of water to run when open, on being 

 laid with pipes, and covered in with soil, worked efficiently ; and 

 the effect is the same in the case of drains with little fall or nearly 

 Level, the water will stand in the drains when open, and even follow 

 the drainer as he finishes the drain, but when it is laid with pipes 

 and covered in, the water will flow immediately. 



Notwithstanding what has been said, however, open drains are to 

 be recommended generally for plantations in respect of their non- 

 liability to be damaged and plugged by the roots of trees. If kept 

 clear of leaves, branches, &c, and cleaned out as often as may be 

 necessary, they will in most cases produce the desired effect, if 

 properly and thoroughly made. It may not be out of place to 

 make some observations in regard to covered or furrow draining, as 

 well as open draining, as there are situations in the range of most 

 foresters, Avhere open drains would be out of place and impracticable. 

 Of the different kinds of covered drains, those laid with pipes or 

 tiles claim the first place, with this qualification, that where stones 

 are abundant, and pipes or tdes are distant, stones may be used for 

 this purpose as a good way of disposing of them, when not required 

 for fencing, road-making, or other estate purposes. 



Covered drains should never be less than 3| feet deep, while 



