The protection of a water frontier--Pile villages of ancient
times--Modern pile dwellings--Their geographic
distribution--River-dwellers in old and popular lands--Man's
encroachment upon the sea by reclamation of land--The struggle with the
water--Mound villages in river flood-plains--Social and political gain
by control of the water--A factor in early civilization of arid
lands--The economy of the water--Fisheries--Factors in maritime
expansion--Fisheries as nurseries of seamen--Anthropo-geographic
importance of navigation.