. Appleton's dictionary of machines, mechanics, engine-work, and engineering. ssing through an opening in its course is therefore applicable in this case as before. It is also ofmoment, both on theoretical and practical grounds, that the sluice be placed as closely upon the wheelas other considerations will permit; and that the retaining cheeks of the aperture, inside of the sluice,be slightly contracted, answering to the natural contraction of the stream after passing through theorifice, in consequence of the resistance which it there encounters. The sides of the course or arc inwhich the whe
. Appleton's dictionary of machines, mechanics, engine-work, and engineering. ssing through an opening in its course is therefore applicable in this case as before. It is also ofmoment, both on theoretical and practical grounds, that the sluice be placed as closely upon the wheelas other considerations will permit; and that the retaining cheeks of the aperture, inside of the sluice,be slightly contracted, answering to the natural contraction of the stream after passing through theorifice, in consequence of the resistance which it there encounters. The sides of the course or arc inwhich the wheel moves, must necessarily be parallel; but, immediately on passing the vertical -planepassing through the axis of the wheel, the floor ought to deepen and the sides expand and leave thewater as much space to diffuse itself over as possible. This arrangement is shown in Figs. 3810 and3811, as far as it is applicable with a sluice-framing entirely constructed of wood ; but, when the con-struction is of iron, the confinement of the water may be made much more complete. Supposing the floats to be placed radially, their breadth or depth in the direction of the radius oughtobviously to be such, that in the rising of the water against the float which it first stokes, the portionwhich tends to pass over its superior edge shall not be thrown against the back of the succeeding action of this kind would manifestly be attended with a corresponding diminution of the effect ofthe wheel; and ought, therefore, to be avoided, as perhaps the most serious error which is liable to becommitted in this form of wheel. This source of loss may, however, be, in general, entirely avoided,by giving to the floats a depth of about three times the thickness of the lamina of water acting uponthem. The thickness of the lamina is usually from four to six inches, giving the range of depth of thefloats from twelve to eighteen inches. The velocity with which the fluid precipitates itself upon the
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Keywords: ., bookcentury1800, booksubjectmechanicalengineering, bookyear1861
