]
[Illustration: The Old Windmill at Work on a Lumberville Farm.]
[Illustration: Fig. 294. Connection of Rod and Crank.]
Action of the Pump.
It was rather a crude pump, but it did all the work we required of it. As
the wheel went around the crank shaft would move the piston up and down.
Whenever the piston went down, the air in the pipe would press up the
edges of the leather disk and squeeze past (see Fig. 295). Then when the
piston came up again, the leather disk, being backed by the wooden disk
beneath it, was kept flat, so that no air could force its way back into
the pipe. This made a partial vacuum in the pipe, and the water from the
well rushed up through the valve at the bottom to fill it (see Fig. 296).
When next the piston went down the bottom valve closed and more air forced
its way past the piston. Then on the next upward stroke more water flowed
into the pipe, until, after a number of strokes, all the air was pumped
out and the water which took its place began to force its way up past the
piston and eventually to flow out of the spout into the cask.
Our old windmill was sold to a farmer near Lumberville when we broke camp
that fall. We carted it over and set it up for him.
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