d adjust the contact
screw until a clear tone is obtained. The rapidly moving armature
of the bell vibrator causes the bottom of the can to vibrate with
it, thus producing sound waves. The pitch of the tone depends on
the thickness of the bottom of the can. This horn, if carefully
adjusted and using two cells of dry battery, will give a soft
pleasant tone that can be heard a block away. If the two
projecting parts of the vibrator are sawed off with a hacksaw, it
can be mounted on the inside of the can. This will make a very
compact electric horn, as only the can is visible. --Contributed
by John Sidelmier, La Salle, Ill.

** Driving a Washing Machine with Motorcycle Power [219]

The halftone illustration shows how 1 rigged up my washing machine
to be driven by the power from my motorcycle. I made a wheel 26
in. in diameter of some 1-in. pine boards, shrunk an iron band on
it for a tire, and bolted it to the wheel on the washing machine.
A long belt the same width as the motorcycle belt was used to
drive the machine. The motorcycle was lined up and the engine
started, then the motorcycle belt thrown off and the long belt run
on, connecting the engine and washing machine wheel. -1. R.
Kidder, Lake Preston, S. D.

[Illustration: Machine Belted to the Motorcycle]

** Home-Made Aquarium [219]

A good aquarium can be made from a large-sized street lamp globe
and a yellow pine block. Usually a lamp globe costs less than an
aquarium globe of the same dimensions. Procure a yellow pine block
3 in. thick and 12 in. square. The more uneven and twisted the
grain the better for the purpose,

[Illustration: Lamp Globe as an Aquarium]

it is then less liable to develop a continuous crack.

Cut out a depression for the base of the globe as shown in Fig. 1.
Pour in aquarium cement and embed the globe in it. Pour more
cement inside of the globe until the cement is level with the top
of the block. Finish with a ring of cement around the outside and
sprinkle with fine sand while the cement is damp. Feet may be
added to the base if desired. The weight of the pine block makes a
very solid and substantial base for the globe and renders it less
liable to be upset.
--Contributed by James R. Kane, Doylestown, Pa

** Protect Your Lathe [219]

Never allow lard oil to harden on a lathe.

** Frame for Displaying Both Sides of Coins [220]

It is quite important for coin collectors to have some convenient
way to

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