Chap. VIII.
323
wherever there arc many acting forces and disturbing causes, the goodness of the channelmay by turns be better or worse; but the grand principles of preservation being main-tained, after a wrong turn happens a right one will succeed, as experience has shown inthe present case; when nature tends rightly, leave her alone; it is time enough to helpher when we are sure she is going wrong.”
kino’s LYNN.
Fig. 325.
Having already discouraged all attempts to prevent the free influx and efflux of the tidesand land waters, in order to preserve the channel out to sea in the most effectual manner,upon which the navigation and drainage by the Ouse entirely depend, he then speaks ofthe banks of the river, and says that they ought to be made stout and high enough to standagainst all extremes ; he disapproves of all jetties built into the stream, as a defence forsaving the banks and foreshores from the action of the water, as they seldom failed of pro-ducing a deep pit, either opposite to or on the downstream side of the jetty, which tends toundermine the banks as well as the jetty itself.
“ All works attempted for the preservation of the foot or bank of foreshores, when toohard a set of the water tends to undermine them, ought to be disposed parallel, or accordingto the direction of the stream, so that the water, instead of being stopped or thrown oiF,shall glide gently by, with the least interruption possible; for thereby the water gets awaywith the least action upon the banks, and wears them or their defences the least. Oilthis account, all angles and sudden turns should be avoided, and when a turn must bemade, let it have as easy a sweep as possible, keeping it near to the natural bend of the river,cutting or rounding off all small sudden turns, angles or exuberances, which may happenin the general sweep.
“ All jetties do mischief, and wherever the sides of a river or foreshore grind away by toogreat stress of water, the most infallible, secure, and lasting method of remedying this is,after the irregularities of the curve are taken away, as low as the water will admit beingperformed by hand, to line up the foot with rubble stones thrown in promiscuously so as toform their own natural slope against the shore, till they appear above low water. Thisbeing done, nature will form for herself such a slope to neap tide high water mark as willneed no artificial defence.
“ The base of the banks and foreshores being secured, and the slope being naturally formedup to the high water mark of neap tides, it will be then sufficiently defended against wavesand currents; above this there is no better way of finishing the wall than by turfing it.No wood should be used at the foot of the turf about neap tide high water mark, but thewhole reliance should be upon a lay of rubble stone, and if some of this be broken, tofill up the interstices of the larger pieces, this will form a more complete union betweenthe rubble and turf than if composed of large stones only.
“ Boarded wharfing is not calculated to stand long against the action of the waves, andsoon goes to decay ; when the sea dashes against the end of a faggot or a stone, these
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