When advancing civilization has eliminated the need for this form of protection, water-dwellers may survive or reappear in old and relatively over-populated countries, as we find them universally on the rivers of China and less often in Farther India. Here they present the phenomenon of human life overflowing from the land to the streams of the country; because these, as highways of commerce, afford a means of livelihood, even apart from the food supply in their fish, and offer an unclaimed bit of the earth's surface for a floating home. Canton has 250,000 inhabitants living on boats and rafts moored in the river, and finding occupation in the vast inland navigation of the Empire, or in the trade which it brings to this port of the Si-kiang. Some of the boats accommodate large families, together with modest poultry farms, crowded together under their low bamboo sheds. Others are handsome wooden residences ornamented with plants, and yet others are pleasure resorts with their professional singing girls.[593] In the lakes and swamp-bordered rivers of southern Shantung, a considerable fishing population is found living in boats, while the land shows few inhabitants. This population enjoys freedom from taxation and unrestricted use of the rivers and fisheries. To vary their scant and monotonous diet, they construct floating gardens on rafts of bamboo covered with earth, on which they plant onions and garlic and which they tow behind their boats. They also raise hundreds of ducks, which are trained to go into the water to feed and return at a signal,[594] thus expanding the resources of their river life. Bangkok has all its business district afloat on the Menam River—shops, lumber yards, eating-houses and merchants' dwellings. Even the street vendor's cart is a small boat, paddled in and out among the larger junks.[595]
A far more modern type of river-dwellers is found in the "shanty-boat" people of the western rivers of the United States. They are the gypsies of our streams, nomads who float downstream with the current, tying up at intervals along the bank of some wooded island or city waterfront, then paying a tug to draw their house-boat upstream. The river furnishes them with fish for their table and driftwood for their cooking-stove, and above all is the highway for the gratification of their nomad instincts. There is no question here of trade and overpopulation.
Reclamation of land from the sea.
Pile dwellings and house-boats are a paltry form of encroachment upon the water in comparison with that extensive reclamation of river swamps and coastal marshes which in certain parts of the world has so increased the area available for human habitation. The water which is a necessity to man may become his enemy unless it is controlled. The alluvium which a river deposits in its flood-plain, whether in some flat stretch of its middle course or near the retarding level of the sea, attracts settlement because of its fertility and proximity to a natural highway; but it must be protected by dikes against the very element which created it. Such deposits are most extensive on low coasts at or near the river's mouth, just where the junction of an inland and oceanic waterway offers the best conditions for commerce. Here then is a location destined to attract and support a large population, for which place can be made only by steady encroachment upon the water of both river and sea. Diking is necessitated not only by the demand for more land for the growing population, but also by the constant silting up of the drainage outfalls, which increases the danger of inundation while at the same time contributing to the upbuilding of the land. Conditions here institute an incessant struggle between man and nature;[596] but the rewards of victory are too great to count the cost. The construction of sea-walls, embankment of rivers, reclamation of marshes, the cutting of canals for drains and passways in a water-soaked land, the conversion of lakes into meadow, the rectification of tortuous streams for the greater economy of this silt-made soil, all together constitute the greatest geographical transformation that man has brought about on the earth's surface.[597]
The struggle with the water.
Though the North Sea lowland of Europe has suffered from the serious encroachment of the sea from the thirteenth to the sixteenth century, when the Zuyder Zee, the Dollart and Jade Bay were formed, nevertheless the counter encroachment of the land upon the water, accomplished through the energy and intelligence of the inhabitants, has more than made good the loss. Between the Elbe and Scheldt more than 2,000 square miles (5,000 square kilometers) have been reclaimed from river and sea in the past three hundred years. Holland's success in draining her large inland waters, like the Haarlem Meer (70 square miles or 180 square kilometers) and the Lake of Ij, has inspired an attempt to recover 800 square miles (2,050 square kilometers) of fertile soil from the borders of the Zuyder Zee and reduce that basin to nearly one-third of its present size.[598] One-fourth of the Netherlands lies below the average of high tides, and in 1844 necessitated 9,000 windmills to pump the waste water into the drainage canals.[599]
The Netherlands, with all its external features of man's war against the water, has its smaller counterpart in the 1,200 square miles of reclaimed soil about the head of the Wash, which constitute the Fenland of England. Here too are successive lines of sea-wall, the earliest of them attributed to the Romans, straightened and embanked rivers, drainage canals, windmills and steam pumps, dikes serving as roads, lines of willows and low moist pastures dotted with grazing cattle. No feature of the Netherlands is omitted. The low southern part of Lincolnshire is even called Holland, and Dutch prisoners from a naval battle of 1652 were employed there on the work of reclamation, which was begun on a large scale about this time.[600] In the medieval period, the increase of population necessitated measures to improve the drainage and extend the acreage; but there was little co-operation among the land owners, and the maintenance of river dikes and sea-walls was neglected, till a succession of disasters from flooding streams and invading tides in the thirteenth and fourteenth centuries led to severe measures against defaulters. One culprit was placed alive in a breach which his own neglect or criminal cutting had caused, and was built in, by way of educating the Fenlanders to a sense of common responsibility.[601]
The fight against the water on the coast begins later than that against rivers and swamps in the interior of the land; it demands greater enterprise and courage, because it combats two enemies instead of one; but its rewards are correspondingly greater. The Netherlands by their struggle have acquired not only territory for an additional half million population, but have secured to themselves a strategic position in the maritime trade of the world.