Periscopes are instruments used to see objects that are not in our direct line of sight. The most common and well-known usage of periscopes is on board submarines, where they are used to look at objects or the area on the surface of the water, while the submarine is underwater. While such periscopes will be well-calibrated, fine instruments, you can also make a simple periscope at home by following the instructions given below.
- 2 quart-sized empty paper milk or juice cartons
- 2 small hand mirrors square-shaped
- Knife or scissors
- Scale and pencil
- Double-sided sticking tape
- Paint or colored construction paper (optional)
Preparing the cartons. Wash the milk cartons thoroughly to remove any residue or odor. Let the cartons dry and then cut-off the top peaked roofs. At the lower end of the front side of one of the cartons. Cut out a small square hole, leaving some space (a quarter each will suffice) at both ends of the carton.
Placing the mirror. Let the carton lie on the table or any flat surface with the cut hole facing towards the right. On the side facing up, mark a point about 2 and three quarters of an inch and using the scale draw a diagonal line reaching the bottom right corner. Starting from the bottom right corner and following the line just made, make a cut on the carton surface as long as the side of the mirror, such that the mirror will fit into the slit made snugly. Slide in the mirror such that the reflecting surface is facing the hole made in the front of the carton. Tape the mirror in place once you've adjusted the mirror in such a manner that you can see the ceiling through the front hole when you hold up the carton to your eye.
Repeat the process. Repeat the process described in steps one and two with the second set of carton and mirror.
Assembling the periscope. Let one carton stand on the table with the hole facing you. Place the other one upside down with the hole facing away from you. With your hands, slightly push in the corners of the second carton, so that it can slide in and fit into the first carton such that you have a long tubular box with mirror edges at the top and bottom ends. Tape the cartons together and your periscope is done! Use the colored paper or paints to cover the surfaces of the carton to make your periscope look attractive and interesting.
When held upright, you can use the bottom hole to look at objects that are over fences and taller than you. If you're looking through the top hole, you can see objects underneath tables or beds, etc. When held horizontally, your periscope will allow you to see around corners!