untain borders of
Transylvania, are among the most sparsely inhabited parts of Europe.[1265]
Japan, ridged by steep volcanic ranges, drenched by mountain-born rains,
strewn with detritus from plunging torrents, can cultivate only 15.7 per
cent. of its area, and is forced to leave 59 per cent. in forest
reserves.[1266]

[Sidenote: Terrace agriculture.]

These figures tell of the hard conditions of life characteristic of most
mountain regions. Population under normal circumstances settles in the
narrow valleys between the ranges and along the borders of their
drainage stream. Soon, however, the food supply becomes inadequate for
the growing numbers, so that artificial means have to be employed to
expand the area of arable land. The soil on the mountain slopes is so
thin that it yields only a scanty return to the labor of tillage.
Moreover, under the operations of ploughing and harrowing, it is exposed
to the danger of washing; so that after a few croppings the underlying
rock of the mountain side may be laid bare, and all that was valuable in
the quondam field deposited in the valley as silt or swept away to
enrich the distant delta of the nearest trunk river.

To obviate this difficulty and to secure the desired increase of arable
land, mountain peoples the world over have resorted to terrace
agriculture. This means hand-made fields. Parallel walls, one above the
other, are constructed on horizontal lines across the face of the steep
slopes, and the intervals between are filled with earth, carried thither
in baskets on the peasants' backs. The soil must be constantly renewed
and enriched by manure in the same way, and the masonry of the retaining
walls kept in repair. Whenever possible these costly terraced fields are
located by preference on southward facing slopes, where the tilt of the
land makes the fields catch the rays of the sun almost at right angles
and thus counteracts the chill of the higher altitude, while the
mountain behind protects the growing crops from cold northern winds.
Good arable land, being limited in amount, commands a high price; and
especially do choice terraced fields in vine-growing countries, since
they make the best vineyards. Such fields in Switzerland will bring from
$300 to $2,000 an acre, and are estimated to produce annually two
bottles of wine for every square foot.[1267]

[Sidenote: Geographical distribution.]

Terrace agriculture, rare in new countries, in the more densely
popu