A periscope is an optical device designed for observation from a covert position. In its simplest form it consists of the tube, which contains parallel mirrors set at a 45-degree angle to the back wall (longitudinal axis) of the tube. There are openings at each end of the tube – the one is for looking through it, and the other one to set it in the direction of an object that we observe. More advanced forms of periscope also contain the system of lenses added to enlarge the image.
The principle of the periscope work: Periscope works on the principle of light reflection from one mirror to another mirror. The mirrors are in the tube inclined at an angle of 45 degree to the longitudinal axis of the tube. The light passes through the top opening and encounters the first mirror. First mirror refract the light rays under 90 degree angle in the direction of the tube longitudinal axis and thus directs them onto another mirror, which also refract the light under 90 degree angle and direct them onto second (bottom) opening. This shows that placing mirrors in a perfectly parallel position is of crucial importance for the work of periscope.
The first periscope was invented by famous Johann Gutenberg in the year of 1430, and it served for watching over the crowd during a religious festival. Periscope with a modern look was created in 17th century and somewhere at that time began its military use. Modern use of periscope began during the World War I, as a device for safe observation of enemy position from the trenches. One of the most famous uses of periscope is in submarines and the periscope today is commonly used for the military purposes (tanks, armored vehicles), but also as a kids toy.
There are various versions of periscope intended for children play. If you lived as a child in a place, where you had a large space for play, you are probably aware of the children need for hiding and spying of another group of children. Children often like to play war games, snow fight, they are dividing into groups, then hide and compete. And if your child would have periscope to use in these type of games, it will be so interesting, because it will have a secret weapon to look over walls or around corners. And you also can use periscope to check some places that normally are not easily visible.
Periscope is a very simple instrument that can be made quite easy. Manufacture of the periscope is frequently included in school programs, as it enables children to learn in practically about basic of optics.
Therefore we present you the periscopetoy plan, by which you can easily make one practical periscope, using just ordinary hand tools. Construction is very simple, with all joints butted and glued.
Periscope toy plan - Parts list
You can adjust the width, length and height of the periscope to suit your need. The only really necessary accuracy is in setting up the mirrors, they must be perfectly parallel. Increasing the periscope height requires greater accuracy during the manufacture, because even a minor deviation of the mirror parallelism can cause periscope not to function, because the reflection of one mirror will not fall onto another mirror.
To build the periscope body, use some lightweight wood or plywood to make it easier to a child to handle the periscope.
Make all parts of the required shape and size.
Periscope toy plan - Parts drawing
You can purchase mirrors in any glass shop, or you can use glass cutter to cut the mirrors on your own from some broken mirror.
After cutting of the parts, but before assembling it, the inner surface of the periscope should be painted white.
Before you start the assemblage, dry fit all the parts and check if the periscope works, and only then glue it permanently.
Thoroughly sand the periscope, round all edges and apply finish. The final finish may be stain or paint.
You should explain to the children how the periscope works, and that they should handle with it carefully, otherwise the mirrors could be broken if it is roughly handled or dropped. We put two narrow corner blocks on each end of the periscope, where the mirrors are glued, but you can put instead one corner block 90mm (3,54in) wide, which is the inner width of the channel.