550

[TEX: \frac{\frac{5^2}{64.33} \times 30 \times 62.5}{550} = 1.32 \text{
the horse power of the current}]

due to the area of the blades of the water wheel.

For the efficiency of this class of wheel, with slightly curved and thin
blades, divide the horse power of the wheel by the horse power of the
current area, equals the percentage of efficiency.

As in the last case,

0.468 / 1.32 = 0.35½

per cent. efficiency of the water wheel.

With higher velocities of stream and wheel the efficiency will be from 2
to 3 per cent. less, although the horse power will increase nearly with
the increase in velocity of the current.

For details of application of various forms of current wheels for power
purposes see illustrated description Yagn's and Roman's floating motors
in SCIENTIFIC AMERICAN SUPPLEMENT, No. 463.

A very good example of a floating motor of the propeller class is
Nossian's fluviatile motor, illustrated and described in SCIENTIFIC
AMERICAN SUPPLEMENT, No. 656.

[Illustration: Fig. 24.]