Page:Popular Science Monthly Volume 72.djvu/233

Rh should be entirely kept from entering behind the wall. At Haining the Chinese engineers have succeeded in accomplishing this very satisfactorily in a twofold fashion—viz., by a sea-foot proper and by frequent projecting "buffers," a combination which, besides giving a substantial sea-barrier, also affords excellent and frequent refuges for the junks whose masters must needs brave the dangers and difficulties of navigation in a river so fiercely tide-swept as this is.

At the level of the sixteenth ledge from the top, in this step-like face of the wall just referred to, i. e., about twenty feet below the top of the wall, there extends outward a heavy granite platform several layers deep and about fifteen feet wide. At the outer edge of this several rows of piles are set close together and deeply driven into the river-bed. Here there is a drop of four or five feet followed by another shelving granite platform, somewhat wider than the first and similarly edged with several rows of much heavier and more numerous piles. Here there is a further drop of six or eight feet to a sandy beach which for a yard or two is rock strewn and studded with piles, a ragged fringe of which about ten feet farther out marks the outer edge of this remarkable barrier.

At intervals of half a mile, at least in the immediate vicinity of Haining, huge projecting buffers in semi-elliptical form have been built of brush and piles. The ends of the brush, which has been stacked and interwoven in horizontal layers, are presented on all sides and down through the mass several concentric rings of stout piles have been