lowing them into the lock
through the keyhole.

** Rust Proofing Bolts [151]

Where bolts are subject to rust, the threads should be painted
with pure white lead; then they will not rust fast.

** Painting Yellow Pine [151]

When painting yellow pine exposed to the weather add a little pine
tar with the priming coat.

** Revolving a Wheel with Boat Sails [152]

A novel windmill or revolving wheel can be made by placing a light
wheel so it will turn freely on the end

[Illustration: An Unusual Type of Windmill]

of a post, and placing four small sailing boats at equal points on
the rim of the wheel. It makes no difference which way the wind
blows, the wheel will revolve in one direction. In Fig. 1 the
direction of the wind is shown by the arrows, and how the sails
catch the wind and cause the wheel to revolve. Figure 2 shows how
the wheel will appear when complete. This device makes an
attractive advertising sign.

** A Floating Electromagnet [152]

A piece of iron placed in a coil of wire carrying a current of
electricity becomes an electromagnet. If such a coil and iron core
be made small enough they can be attached to a cork and the cork,
floating on a solution, will allow the magnet to point north and
south. The sketch shows how to make such an instrument. A coil of
insulated wire is wrapped around a small iron core, leaving a few
inches of each end free for connections. The insulation is removed

[Illustration: Floating Electromagnet]

from these ends and they are run through a piece of cork. Attach
to the wires, on the under side of the cork, a piece of zinc to
one end and a piece of copper to the other. The cork is then
floated on a solution of acid, with the zinc and copper hanging in
the solution. If zinc and copper are used, the solution is made
from water and blue vitriol. If zinc and carbon are used, the
solution is made from sal ammoniac and water.

The float will move about on the solution until the magnet iron
will point north and south. If two of them are floating on the
same solution, they will move about and finally arrange themselves
end to end with the coils and magnet cores pointing north and
south.
--Contributed by C. Lloyd Enos.

** A Fish Bait [152]

A very effective fish bait is made by inclosing a live minnow in a
short section of glass tube, which is filled with water and both
ends closed with corks. This is used in place of the spoon.

** Homemad