GROWING TIMBER, 129 
practically ceased to grow, a little anticipation of the natural 
result may be desirable in the case of the latter, and the re- 
moval of the smaller trees gradually effected before the main crop 
becomes too spindly. In either case the principle is the same, but 
the adaptation of the principle to concrete cases constitutes the real 
skill of the culturist. 
Of course the age at which it is intended to cut the crop, and the 
size of timber required, greatly modify the system of treatment. 
Where timber of less than 12 inches quarter-girth fetches as good a 
price per cubic foot as that of larger dimensions, thinning might 
almost be dispensed with altogether on the better soils, merely 
removing the suppressed trees at intervals of five years or so, 
according to convenience. Thus treated, the crop should be fit to 
cut about the seventieth year. Where additional size is accom- 
panied by an increase in price, however, it would be more profitable 
to thin the crop carefully, commencing about the fortieth year, or 
about the period at which height-growth usually culminates, and 
repeating the operation at intervals until from one-half to two- 
thirds of the trees have been removed. The final felling may be 
made about the hundredth year or so, according to the growth and 
health of the trees. On the best Scots pine soils in North Germany, 
rotations of one hundred and forty years are frequently adopted ; 
but this period would probably be too long for the poor soils in 
most parts of Scotland, where the height-growth is less, and 
finishes earlier. 
On poorer soils it is advisable to attend to thinning about tle 
twenty-fifth or thirtieth year, thinning most freely at high eleva- 
tions, so that the one operation may suffice, as there will be little 
danger of the trees developing a bushy side-growth in such 
situations. 
The total yield expected from an acre of Scots pine varies with 
soil, age, and climate; but about 8000 to 10,000 feet from the 
thinnings and final felling would be about the average on the 
better soils, falling to 4000 or 5000 feet on less favourable situa- 
tions with short rotations. At an average price of 4d. per cubic 
foot, this would represent a gross return of £130 to £150 per acre 
on the former, and £50 to £60 on the latter. In spite of the 
relatively low value of the timber, therefore, Scots pine probably 
yields a better return on poor soils than any other tree we could 
grow, except, of course, larch. This is greatly due to the low 
cost at which planting can be done, and the small rental charged 
