How to Build a Periscope?

Take the top of the milk carton off. Cut a square hole at the bottom of one side of the milk carton. It should be window like, with about 1/4 to 1/2 inch of carton left on the sides and the bottom of the hole. Slide a square mirror into the window, at a 45 degree angle. One end of the mirror should touch the bottom border of the opening, and the other end to the opposite wall of the carton. Tape the mirrow straight into place. You don’t want the mirror to be crooked. Do steps 1-3 for another carton. Attach the milk cartons together, open end to open end, to form a tube. There should be 2 mirrors, one each on the top and the bottom. They need to face opposite directions. Look through it and see what you see.