The application of steam to industry has converted mountain regions of abundant mineral wealth into centers of production for the markets of the world.  But this is the history of only the last century, and of only favored mountain regions.  The utilization of waterpower for electricity in factories is transforming the piedmont belts of the Alps and Apennines; but life in the interior of these ranges remains unaltered by the denser population at their base, except for the increased demand for the butter, milk and cheese of the highland pastures.  For the world at large, therefore, the obvious and persistent fact of mountain economy is a scanty food supply secured by even the most intelligent and untiring labor, and a fixed tendency to overpopulation.  The simplest remedy for this evil is emigration, a fact which Malthus observed.[1328] Hence emigration is an almost universal phenomenon in highland regions.  Sometimes it is only seasonal.  It takes place in the fall after the field work is over, and is due to the paucity of industries possible in the mountains during the winter.  It seems to be a recurrence of that nomadic note in the motif of mountain life—­that migration in summer upward to the borders of the snow, in winter downward to the sun-warmed plains.  In autumn the Swiss descend from the Jura and Alps in great numbers to cities, seeking positions as servants or pastry-cooks.  The Auvergnats leave their home by the thousand in the fall, when snow covers the mountains, to work in the cities as hewers of stone and drawers of water, then return in summer to resume their tasks in field and pasture, bringing back sums of money which noticeably enrich the home districts.[1329]

[Sidenote:  Forms of temporary emigration.]

This seasonal emigration often assumes the form of peddling, in order to dispose of small home-made wares.  From the Basilicata and Modena Apennines the young men follow the pedler’s trade, but the Basilicata village of Viggiano furnishes Italy with many wandering musicians.[1330] The Kabyles of the Atlas Mountains go out in parties of two or three in the fall, and hawk every kind of goods, bringing back from their journey quantities of wool for home weaving.[1331] The emigration may last for several years, but finally the love of home generally calls the mountaineer back to his rugged hills.  The Galicians of the Cantabrian Mountains of northern Spain leave their poor country for a time for the richer provinces of Portugal and Spain, where they become porters, water-carriers and scavengers, and are known as boorish, but industrious and honest.  The women from the neighboring mountain province of Asturias are the professional wet-nurses of Spain.  They are to be seen in every aristocratic household of Madrid, but return to the mountains with their savings when their period of service ends.[1332] In mountainous Basutoland, the Kaffir Switzerland of South Africa, arable land and pastures are utilized