98 OUR FORESTS AND WOODLANDS 
trees to have a better crown of foliage and to 
thicken in girth. Neglect to thin at the proper 
moment would of course lead to a crowded and 
unhealthy condition, which is just as much to be 
avoided as too open a growth. It is thus that 
oak forests are treated in some parts of conti- 
nental Europe, where they are made to attain a 
maximum height of from a hundred to a hundred 
and thirty feet, often with a clean stem for about 
two-thirds of their length. The height attain- 
able depends, however, to a very great extent on 
the depth and the general suitability of the soil. 
On deep fresh loams and in cool, shady dingles 
and dells the oak is less impatient of shade or of 
lateral confinement than on light sandy soils or 
warm exposures, where its natural demands for 
light and air become very marked. The soils 
that in general suit the oak best are deep heavy 
clay soils or stiffish loams, though it also does well 
on lighter loamy and sandy soils that are deep 
and fresh. But the largest trees and the finest 
quality of wood are produced on deep clay lands. 
In its natural habit of growth the oak exhibits 
as necessitous a demand for light and air during 
the young pole stage of growth as any other of 
