Cubic feet water discharged , . , . .,

-----------------------------------= No. corresp. to height, as per table.

Area orifice, sq. inches

The Velocity of Water issuing from an Orifice in the Side or Bottom of a Vessel being ascertained to be as follows:

√Height ft. surface above orifice X 5.4 =

Velocity of water, ft. per second.

√Height ft. X Area orifice, ft. X 324 =

Cubic feet discharged per minute.

√Height ft. X Area orifice, ins. X 2.2 = Do. Do.

It may be observed that the above rules represent the actual quantities that will be delivered through a hole cut in the plate: if a short pipe be attached, the quantity will be increased, the greatest delivery with a straight pipe being attained with a length equal to 4 diameters, and being 1/3 more than the delivery through the plain hole; the quantity gradually decreasing as the length of pipe is increased, till, with a length equal to 60 diameters, the discharge again equals the discharge through the plain orifice. If a taper pipe be attached, the delivery will be still greater, being 1½ times the delivery through the plain orifice; and it is probable that if a pipe with curved decreasing taper were to be tried, the delivery through it would be equal to the theoretical discharge, which is about 1.65 the actual discharge through a plain hole.

To find the Quantity of Water that will run through any Orifice, the top of which is level with the Surface of Water as over a Sluice or Dam.

= Cubic feet discharged per minute.

Or,

Two-thirds area of water passage, sq. ins. X No. corresponding to height as per table = Cubic feet discharged per minute.