188G.] LETTERS TO THE EDITOIi. 651 



point, capable of penetrating to a very great deptli, and through 

 strata quite impervious to most other roots. I remember seeing 

 some remarkably fine oak trees growing on the Downton Castle 

 estate (]\Ir. Ludlow), on some Silurian rocks, with a very little depth 

 of soil. The river Teme runs through this estate ; in some places 

 the banks are precipitous. I am afraid to say — after the lapse of 

 some thirty-five years — how far it was from the trunk of the trees 

 on the top to the water, but should think it might be 50 or 60 feet. 

 J remember noticing that the roots of these trees have followed the 

 interstices in the rocks till they had reached the bed of the river. 

 It is thought that in most cases the tap-root of an oak will pene- 

 trate to a deptli equal to the height of the tree; it is therefore of 

 great importance that the tap-root should never be injured. There is, 

 however, a serious drawback in growing oaks from acorns, and that 

 is the very slow growth of the first two or three years, consequently 

 they are very liable to destruction from hares and rabbits; a severe 

 winter would be fatal to any number of acres, if there were only a 

 moderate number of these animals in the neighbourhood, as hares 

 will travel miles to feed on them. 



I think the best and cheapest way of planting acorns is to plough 

 a furrow about four inches deep, say about a yard or four feet apart, 

 then strew the acorns thinly along the bottom, and turn the furrow 

 back, treading it well down. I think this preferable to diljbling, as 

 if two or three acorns should each germinate, the chances are the 

 roots would intertwine, and it would be difficult to thin them. I do 

 not attach much value to the cleaning of the ground, as the vegeta- 

 tion of grasses would be more of a protection to the young trees ; 

 but any rank vegetation, such as fern, gorse, or heather, must be 

 kept under, or the young plants would be smothered. I recommend 

 a thicker planting than you do, in order that a sufficient number 

 may be left to select the best grown and most vigorous trees for 

 standards. If there is much risk of hares or rabbits, it may be worth 

 while to surround the plantation with wire-netting. 



Your article on Drainage of Land for Plantation Purposes will 

 render any remarks on this subject superfluous. — Yours truly, 



Wm. Mainwaring. 



Bainfiet.d, 9</( January 1886. 



WHAT IS BEBENTUBE WOOB ? 



DEAR SIR, — Can any of your readers inform me of the meaning 

 of Debenture Wood ? It is a species of mining timber, large 

 size and partially square, and is imported from the Baltic into Hull. 

 A friend of mine — the secretary of a large Lancashire firm of 



