144 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
to the Jurassic formation, which is well suited to the growth of 
beech, while the summit of the hills, and the north-east slope, 
belong to a Wealden sandstone, which at the hill-foot gives place 
to the Wealden clay. This sandstone forms a good sandy loam, 
which, where sufficiently deep and moist, is well adapted to the 
growth of all trees, but is chiefly stocked with oak and spruce. 
Where grown in pure woods, the length of the rotation is 
160 years for the oak, 120 years for the beech, and 80 years for the 
spruce. Pure oak woods, however, are only found on the strong 
loam near the base of the hills; elsewhere this tree is generally 
mixed with beech, sycamore, and ash. 
Beech is, on the whole, the principal tree of the Deister, and is 
propagated entirely by means of self-sown seed. In this district 
seed is borne every third year or so, and with proper management 
there is no difficulty in obtaining an abundant supply of young 
plants. The usual plan is to introduce strong periodic thinnings 
—removing about 1000 cubic feet of timber per acre each time— 
from the eightieth year onwards. This encourages the trees to 
bear abundance of seed, and, by admitting light and rain, induces 
more rapid decomposition of the leaf-mould that covers the ground, . 
and so prepares a good seed-bed. 
The spruce is cultivated entirely by planting, seedlings or trans- 
plants being used according to the character of the ground. The 
former are usually planted in bunches, a style of planting 
practically unknown in Scotland. The spruce woods are thinned 
for the first time when they are about twenty-five years old, the 
operation being repeated every six or eight years. The beech 
woods, on the other hand, are not thinned for the first time till. 
they are about thirty-five years old. 
The annual yield per acre over all averages about 43 cubic feet 
quarter-girth measurement, which is equal to about 57 cubic feet 
of actual wood, slabs included. Of the total out-put, 65 per cent. 
of the oak, 25 per cent. of the beech, and 75 per cent. of the spruce 
is classed as timber, the rest being used as firewood. The average 
prices for timber during the last few years—calculated on the 
English system of measurement—have been 
Oak, . 4 “ - about 1s. per cubic foot. 
Beech, : : - » 64d. FS 
Spruce, 5 ’ . 55 2 OG a 
Beech wood for burning purposes sells at about 17s. per cord. 
1 In converting cubic metres per hectare into cubic feet per acre, I have taken. 
35°83 cubic feet as being equal to 1 cubic metre, and 2°47 acres as equal to 1 hectare.” 
I have then reduced the volume so found by 25 per cent., because our system 
of measuring timber (the quarter-girth system) gives only about three-quarters 
of the volume got by the German system (the middle sectional area multiplied 
by the length). : ; 
