the outer edge of the shelf. The
support, A, Fig. 2, should be long enough to extend diagonally to
the floor or top of the baseboard from the inner edge of the cleat
when the shelf is up in its proper place. --L. L.

** Home-Made Electric Battery Massage [144]

A simple and cheap electric massage device can be made by using
three or

[Illustration: Electric Massage]

four cells of dry battery connected to two ordinary silver
tablespoons, as shown in the sketch. The handles of the spoons
should be insulated or the operator can wear either kid or rubber
gloves.

** How to Make Tint Lantern Slides [144]

Purchase some lantern slide plates and fix them in hypo without
exposing, in the usual manner, same as you would an exposed plate,
says the Moving Picture World. This leaves a thin, perfectly
transparent emulsion film on the glass, which will readily take
color. Mix a rather weak solution of clear aniline dye of the
desired color and dip the plate in it, wiping the plate side
clean. If not dark enough, dip again and again until desired tint
is attained, letting it dry between each dipping. A very light
blue tint slide will brighten a yellow film considerably, but the
tint must be very light, just a bare tint.

** A Bicycle Catamaran [145]

The accompanying photographs show a bicycle boat made to carry two
persons.

[Illustration: This Catamaran Carries Two People]

This boat is constructed by using two galvanized iron tubes 18 ft.
long and 12 in. in diameter, tapered at the front end down to
cast-iron points, and the rear end shaped to attach rudders. These
tubes are placed 26 in. apart, giving the boat an extreme width of
50 in.

The cylinders support a platform and on the rear end of this
platform is constructed a paddle wheel 52 in. in diameter with 16
spokes. On the end of each spoke is fastened a galvanized sheet
metal blade 6 in. wide and 8 in. long. A large guard placed over
the paddle wheel forms a seat for one person and a chair in front
on the platform provides a place for a second person.

The person in front helps to propel the boat with hand levers
which are connected with rods to sprocket wheels on each side of
the platform. The occupant of the rear seat contributes his part
of the power with his feet on pedals of the shaft that carries the
sprocket wheels. This shaft and sprocket wheels drive the paddle
wheel by side chains of the bicycle kind. The boat is steered from
the rear