276 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY, 
in the meantime—and this can easily be done from the contour- 
lines on the Ordnance Survey maps. 
The road-system should be so planned that the whole area 
can be divided into main sections of about 440 yards square 
(40 acres), subdivided, if convenient, by narrower roads (220 
yards apart) into 1o-acre compartments, and having one side at 
right angles to the most dangerous prevailing wind (generally 
the S.W.). Shelters-belts should then be formed about 20 to 30 
yards wide along the windward edge of each main section, if the 
planting of the whole area is intended to be accomplished within 
say ten years,—or along the windward edge of each alternate 
section, if it be desired to extend the planting over about twenty 
years,—and the intervening stretch can be marked off as thg 
areas to be successively planted during each of the next ten 
or twenty years. The planting of such shelter-belts with quick- 
growing thickly-foliaged pines and firs should precede the plant- 
ing of the rest of the area by at least five years, so as to allow 
the belts to establish themselves and thus become able to afford 
substantial protection against cutting winds to the younger strips 
of plantation successively formed year by year to the leeward 
of them. 
Moorland peat-bogs are generally water-logged and rest on 
an impervious clay subsoil. Such cold land only produces 
stunted pine, birch, aspen, willow, and alder, in its unreclaimed 
state, or merely bears an unproductive soil-covering of heath, 
heather, and rough grasses and bog-plants. Even after drainage 
it usually remains dull and inert at first, though it often forms 
good woodland soil on becoming more earthy. Thorough 
drainage of such land by deep open trenches is necessary before 
planting can have any chance of succeeding, and after the 
drains are opened the land should le fallow from twelve to 
eighteen months. 
Unless drainage can be done cheaply and the mineral soil 
can be soon reached, there is small chance of peat-bogs being 
plantable with profit, as even well-drained hags of dripping 
peat will only grow Scots pine intermixed with birch, aspen, 
and also spruce in sheltered parts. On the better classes of 
bog and peat land white willow and common and Canadian 
black poplars sometimes do well, and may then prove the 
most profitable trees that can there be grown. Sometimes 
oak and ash can thrive on well-drained mossy soil resting 
