he outline and file the edges smooth.

Cover the metal over with two coats of black asphaltum varnish,
allowing each coat time to dry. Cover the back and all the face
except the white background. Immerse in a solution of 3 parts
water, 1 part nitric acid and 1 part sulphuric acid. When the
metal has been etched to the desired depth, about 1-32 of an inch,
remove it and clean off the asphaltum with turpentine. Use a stick
with a rag tied on the end for this purpose so as to keep the
solution off the hands and clothes. The four pieces should be
worked at the same time, one for each corner.

It remains to bend the flaps. Place the piece in a vise, as shown
in Fig. 2, and bend the flap sharply to a right angle. Next place
a piece of metal of a thickness equal to that of the blotter pad
at the bend and with the mallet bring the flap down parallel to
the face of the corner piece, Fig. 3. If the measuring has been
done properly, the flaps

[Illustration: Manner of Forming the Plates]

ought to meet snugly at the corner. If they do not, it may be
necessary to bend them back and either remove some metal with the
shears or to work the metal over farther. All the edges should be
left smooth, a metal file and emery paper being used for this
purpose.

If a touch of color is desired, it may be had by filling the
etched parts with enamel tinted by the addition of oil colors,
such as are used for enameling bathtubs. After this has dried,
smooth it off with pumice stone and water. To keep the metal from
tarnishing, cover it with banana-oil lacquer.

** Boring Holes in Cork [8]

The following hints will be found useful when boring holes in
cork. In boring through rubber corks, a little household ammonia
applied to the bit enables one to make a much smoother hole and
one that is nearly the same size at both openings. The common
cork, if rolled under the shoe sole, can be punctured easily and a
hole can be bored straighter. The boring is made easier by boiling
the cork, and this operation insures a hole that will he the
desired size and remain the size of the punch or bit used.

** Self-Lighting Arc Searchlight [9]

A practical and easily constructed self-lighting arc searchlight
can be made in the following manner: Procure a large can, about 6
in. in diameter, and cut three holes in its side about 2 in. from
the back end, and in the positions shown in the sketch. Two of the
holes are cut large enough to hold a short s