tical uses as well. In a store or other
place where a person on duty cannot
watch all parts of the establishment.
SIDE VIEW FRONT VIEW
This Simple Periscope Is Useful Both for Play and
such a device is convenient in that it
will reflect persons entering the door.
As a toy or for experimental purposes
the periscope shown has many possibilities, and will appeal to youngsters.
It consists of a square box, 18 in.
long, open at the ends. It is 3½ in.
wide and made of wood, .375 in. thick.
A mirror is fitted at an angle of 45° near
one end of the box or tube, as shown in
the sketch. The front of the mirror is
opposite a three-cornered opening in
the box which extends across one side.
The opposite end of the tube is also
fitted with a mirror in the same manner, except that the front of the mirror
faces to the opposite side of the box
at which there is also an opening. In using this device, the user
sights from the point indicated by the
eye. The image is reflected in the
mirror at the top and thrown onto
the lower mirror, where it may be seen
without exposing the head above the
level of the lower opening. It is this
application of reflection by mirrors that
makes it possible for soldiers to see distant objects without exposing themselves to fire, by the use of the periscope.