-: MAKING A PERISCOPE :-

A periscope is an optical instrument with which a person can see around corners and other obstractions. It consists of a long tube with a reflecting mirror or prism at each end. The reflecting surfaces are parallel to one another. They are arranged at an angle of 45⁰  inside the tube. Periscopes are important instruments used in submarines and tanks. They are also used by soldiers in the battlefield.

-: MATERIALS REQUIRED :-

• Take a cardboard tube and two small mirrors. Use a small hacksaw to cut a section near each end of the tube. First make a horizontal cut to about 3/4 of the diameter of the tube. Now make two cuts at 45⁰ to the horizontal cuts. Use a 45⁰  set-square for guidance while making these cuts. 

• Glue the mirrors in places where the sloping cuts have been made. The silvered surfaces of the mirror should face each other so that light can pass through the instrument.