ight. The main feature of this adjuster is
that it can be removed from the cord at any time. The adjuster is
made from a piece of wood, 3/8 in. thick, 2 in. wide and 3 in.
long. A 1/4 in. hole is bored in the center near each end of the
wood and a slot cut from

[Illustration: Can Be Taken from the Cord]

the holes to the outside edge, as shown in Fig. 1. It is attached
to the flexible cord as shown in Fig. 2.
--Contributed by J.J. Voelcker; Decatur, Ill.

** Making Photographs on Watch Dials [386]

Beat to a foam the white of an egg, with the addition of a little
ammonia. Add 9 oz. and 3 dr. of water and beat again. After the
egg has settled, filter and let the liquid run over the dial,
which has been previously cleaned with ammonia. When the surplus
has run off, coat with the mixture and allow to dry.

A sensitive collodion is now produced as follows: Dissolve 9 gr.
of chloride of zinc in 5 dr. of alcohol; add 7-1/2 gr. of
collodion cotton and 6-1/2 dr. of ether. Shake the whole forcibly.

Dissolve 23 gr. of nitrate of silver in hot water, add 1-1/2 dr.
of alcohol and keep the whole solution by heating. The silver
solution is now added in small quantities at a time to the
collodion, which must be well settled. This, of course, is done in
the dark room. After 24 hours the emulsion is filtered by passing
it through cotton moistened with alcohol. This durable collodion
emulsion is now flowed thinly upon the prepared watch dial, which,
after the collodion has coagulated, is moved up and down in
distilled

water until the fatty stripes disappear. The water is then
changed once, and after a short immersion, the dial is left to
dry on a piece of blotting paper. It is now ready for exposure.
Expose under magnesium light and develop with a citrate
oxalic developer, or in the following hydroquinone developer:

Hydroquinone .............1 dr.
Bromide of potassium .... 6 dr.
Sulphite of soda......1-1/2 oz.
Carbonate of soda ....2-2/3 dr.
Water....................14 oz.

After fixing and drying, coat with a transparent positive varnish.

** Home-Made Overhead Trolley Coaster [387]

The accompanying sketch shows a playground trolley line which
furnished a great deal of amusement to many children at a minimum
cost. The wire, which is 3/16 in. in diameter, was stretched
between a tree and a barn across a vacant quarter block. The
strength of the wire was first tested by a heavy man. When n