Question

What is a periscope?what is it used for

Answer 1

periscope is a type of scope which used in submerins

Answer 2

Periscope is an instrument which is used for observation from a concealed position. In its simplest form it consists of an outer case with mirrors at each end set parallel to each other at a 45 degree angle. This form of periscope, with the addition of two simple lenses, served for observation purposes in the trenches during word war I.