power with the reaction turbine, whereas it would be
useless with an impulse wheel. Falls of from five to fifteen feet are
to be found on thousands of farm streams, and the reaction turbine is
admirably adapted to them.

Reaction turbines consist of an iron "runner" which is in effect a
rotary fan, the pressure and momentum of the column of water pressing
on the slanted blades giving it motion and power. These wheels are
manufactured in a great variety of forms and sizes; and are to be
purchased either as the runner (set in bearings) alone, or as a runner
enclosed in an iron case. In case the runner alone is purchased, the
owner must enclose it, either with iron or wood. They vary in price
according to size, and the means by which the flow of water is
controlled. A simple 12-inch reaction turbine wheel, such as would be
suitable for many power plants can be had for $75. A twelve-inch
wheel, using 18 or 20 square inches of water, would generate about
7-1/2 horsepower under a 20-foot head, with 268 cubic feet of water a
minute. Under a 30-foot head, and with 330 cubic feet of water such a
wheel will give 14 horsepower. A 36-inch wheel, under a 5-foot head,
would use 2,000 cubic feet of water, and give 14 horsepower. Under a
30-foot head, this same wheel, using 4,900 cubic feet of water a
minute, would develop over 200 horsepower. If the farmer is confronted
by the situation of a great deal of water and small head, a large
wheel would be necessary. Thus he could secure 35 horsepower with only
a 3-foot head, providing his water supply is equal to the draft of
8,300 cubic feet a minute.

From these sample figures, it will be seen that the reaction turbine
will meet the requirements of widely varying conditions up to, say a
head of 100 feet. The farmer prospector should measure first the
quantity of water to be depended on, and then the number of feet fall
to be had. The higher the fall, with certain limits, the smaller the
expense of installation, and the less water required. When he has
determined _quantity_ and _head_, the catalogue of a reputable
manufacturer will supply him with what information is necessary to
decide on the style and size wheel he should install. In the older
settled communities, especially in New England, a farmer should be
able to pick up a second-hand turbine, at half the price asked for a
new one; and since these wheels do not depreciate rapidly, it would
serve his purpose as well, in most cases,