Things You'll Need
Instructions
Cut the tops off of both cereal boxes. Trace the top of the cereal box onto the piece cardboard twice, then cut out both pieces.
Tape or glue one mirror to each of the pieces of cardboard.
Put glue around the edges of the pieces of cardboard. Then put one in each of the cereal boxes so that it sits on the bottom at a 45-degree angle.
Cut a small square hole in each of the cereal boxes just above where it meets the lower edge of the mirror. One of these will function as a slot for viewing and the other will allow light to enter the chamber.
Place the cereal boxes on top of each other with the open ends together and the angles of the mirrors parallel. Each of the square holes will be on opposite sides of the periscope. Look through the bottom square hole to view what's happening above.