n: Details of the Post Card Lantern]

vertically, AA, as shown in Fig. 1, 3-1/2 in. from each end. An
open space 4 in. wide and 5 in. high in the center is for the part
carrying the lens to slide for focusing. The part carrying the
lens is a shallow box 4 by 5 in. and 2 in. deep in the center of
which a hole is cut to admit the lens. If a camera lens is used,
the flange should be fastened with screws to the front part of
this shallow box. The sides of this box should be made quite
smooth and a good, but not tight, fit into the runners. Plumbago
can be rubbed on to prevent sticking and to dull any rays of
light.

Two keyless receptacles for electric globes are fastened to the
under side of the top in the position shown and connected with
wires from the outside. Two or three holes about 1 in. in diameter
should be bored in the top between and in a line with the lights.
These will provide ventilation to keep the pictures from being
scorched or becoming buckled from the excessive heat. The holes
must be covered over on the top with a piece of metal or wood to
prevent the light from showing on the ceiling. This piece should
not be more than 1/2 in. high and must

[Illustration: Post Card Lantern Complete]

be colored dead black inside to cause no reflection.

The reflectors are made of sheet tin or nickel-plated metal bent
to a curve as shown, and extending the whole height of the
lantern. The length of these reflectors can be determined by the
angle of the lens when covering the picture. This is clearly shown
by the dotted lines in Fig. 1. The reflectors must not interfere
with the light between the picture and the lens, but they must be
sufficiently large to prevent any direct light reaching the lens
from the lamps. In operation place the post card upside down in
the slides and close the door. Sliding the shallow box carrying
the lens will focus the picture on the screen.

** A Handy Calendar [196]

[Illustration: The Knuckles Designate the 31 Day Months]

"Thirty days hath September, April, June and November," etc., and
many other rhymes and devices are used to aid the memory to decide
how many days are in each month of the year. Herewith is
illustrated a very simple method to determine the number of days
in any month. Place the first finger of your right hand on the
first knuckle of your left hand, calling that knuckle January;
then drop your finger into the depression between the first and
second knuckle