he center and a block nailed to
the larger tower spaced the wheel far enough out so that the cans did
not strike the tower as they revolved. We carefully measured the
distance between the spokes and the larger tower, and then built a
square trough of a size to just fit into this space. This trough was
nailed across the end of the V-shaped trough on top of the tower, but a
notch was cut in the side so that the water would pour from the square
or receiving trough into this V-shaped one. The square trough was about
8 feet long and its sides were 12 inches high; but at the ends we had to
cut them down to a height of but 6 inches, so as to permit the cans to
pass without hitting them.

SETTING UP THE TOWERS.

Our filter was located nearly 20 feet from the end of the river, and in
order to get a good current of water to revolve our wheel we had to
place it about 15 feet from shore. This necessitated building a trough
line 35 feet long. Ten feet of this line were already provided in the
top of the tall tower. This tower was now set up in place with the legs
firmly wedged into holes excavated in the bottom of the river. The legs
on the shore side were sunk a little deeper, so as to tilt the trough
slightly shoreward. The outer end of the trough was about 12 feet above
the level of the water. We needed but one more tower to support the
remainder of the trough line. This tower was built like the first one,
but was much shorter, as it was erected on land and the level of the
trough at the top had to be 5 or 6 inches lower so as to make the water
flow. We connected the towers by another V-shaped trough section. This
we nailed to the under side of the first trough and to the inside of the
second trough. The latter was then in the same way connected by a trough
section with the upper filter barrel. We now rigged up our shorter tower
about a foot from the taller one, wedging in the legs so that the top
came level with the slotted boards of the other tower.

MOUNTING THE WATER WHEEL.

Then came the task of mounting our wheel in place. We were working in a
pretty strong current and found it no easy matter. In the first place,
the wheel was floated down to the towers, but there it got jammed and we
couldn't lift it up. One of the paddles was broken and a bucket wrenched
off before we could disentangle the wheel from the towers, and then the
wheel was carried quite a distance down-stream before we could drag it
in to shore.

Our