the number of
revolutions per minute required, according to the position to which the
governing mechanism has been set or adjusted.

If the velocity of the wind is such that the pressure on the side vane
overcomes the resistance of the counter weight, then the side vane is
carried around parallel with the rudder vane, presenting only the edge
of the wind wheel or ends of the fans to the wind, when the mill stops
running.

This type of mill presents more effective wind receiving or working
surface when in the wind, and less surface exposed to storms when out of
the wind, than any other type of mill. It is at all times under the
control of an operator on the ground.

A 22-foot Eclipse mill presents 352 square feet of wind receiving and
working surface in the wind, and only 91/2 square feet of wind resisting
surface when out of the wind.

Solid-wheel mills are superseding all others in this country, and are
being exported largely to all parts of the world, in sizes from 10 to 30
feet in diameter. Many of these mills have withstood storms without
injury, where substantial buildings in the immediate vicinity have been
badly damaged. I will refer to some results accomplished with pumping
mills:

In the spring of 1881 there was erected for Arkansas City, Kansas, a
14-foot diameter pumping wind mill; a 32,000-gallon water tank, resting
on a stone substructure 15 feet high, the ground on which it stands
being 4 feet higher than the main street of the town. One thousand four
hundred feet of 4-inch wood pipe was used for mains, with 1,200 feet of
11/2-inch wrought iron pipe. Three 3-inch fire hydrants were placed on the
main street. The wind mill was located 1,100 feet from the tank, and
forced the water this distance, elevating it 50 feet. We estimate that
this mill is pumping from 18,000 to 20,000 gallons of water every
twenty-four hours. We learned that these works have saved two buildings
from burning, and that the water is being used for sprinkling the
streets, and being furnished to consumers at the following rates per
annum: Private houses, $5; stores, $5; hotels, $10; livery stables, $15.
At these very low rates, the city has an income of $300 per annum. The
approximate cost of the works was $2,000. This gives 15 per cent.
interest on the investment, not deducting anything for repairs or
maintenance, which has not cost $5 per annum so far.

[Illustration: Plate 2. THE ECLIPSE WIND MILL.]

In June, 1883, a wind wa