Water-power; an outline of the development and application of the energy of flowing water . he chain is perfectlysimple. When the water-pressure is off the shutters theymight be liable to the same difficulty as is met with in the caseof flashboards supported against pins, \-iz., being lifted off theprops by the pressure of the wind and allowing the latter tofall. This would be obviated by employing the form of hingeshown at Figs, job and joc, which limits the movement of theshutter, and allows it to be strained up with considerable forcebefore inserting the prop. The fall of the shutter is cus
Water-power; an outline of the development and application of the energy of flowing water . he chain is perfectlysimple. When the water-pressure is off the shutters theymight be liable to the same difficulty as is met with in the caseof flashboards supported against pins, \-iz., being lifted off theprops by the pressure of the wind and allowing the latter tofall. This would be obviated by employing the form of hingeshown at Figs, job and joc, which limits the movement of theshutter, and allows it to be strained up with considerable forcebefore inserting the prop. The fall of the shutter is cushionedby the body of water beneath it, which can never fail to bepresent when the necessity arises for throwing down thebarrier. When lying flat on the masonry the shutter can re-ceive no injury from floating bodies. The only injury to beapprehended from the fall of the shutter is from extraneous I=iO APPENDAGES OF DAMS. bodies lying on the dam. The props need not be sacrificed asare the boards in the ordinar\- arrangement, as they can beattached to the main chain and hauled in with Fig. -,ob. Fig. IOC. —Certain species of fish, dwelling habitually insalt water, are capable of existence in fresh water, and areendowed with an instinct which impels them to ascend riversat certain seasons of the }-ear, there to deposit their spawn,after which they return to salt water. The \oung also returnto salt water, and after reaching the age of reproduction, two,three, or four years, return to the grounds where their ownexistence commenced, and revisit the same grounds annuallythereafter. This fact has been unmistakabh verified by theUnited States Fish Commission. The chief varieties of fish possessed of this characteristicare salmon, shad, and alewiv^es. So imperious is the migratoryinstinct that no common obstacle can arrest the upwardprogress of these fish. They make their way through foamingrapids, and easily surmount a perpendicular fall of considerableheight. At Curryt
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecthydraulicengineering
