Re: how does a periscope work?

A periscope works by using two mirrors to bounce light from one place to 
another.  A typical periscope uses two mirrors at 45 degree angles to the 
direction one desires to see.  The light bounces from one to the other and 
then out to the persons eye.  I have included a picture of a typical 
periscope designe.  A periscope is designed to allow a person to see around 
an object or through a wall.  Often used by the military, periscopes allow 
people to look at things without putting themselves in danger.  Periscopes 
are often used by the army to see above or around a wall or obstacle.  
Periscopes in the navy are used on submarines to allow the crew to see above 
the water, without having to surface the whole sub.  Happy periscoping!