Periscope

A periscope is an instrument for observation from a concealed position. In its simplest form it is a tube in each end of which are mirrors set parallel to each other and at an angle of 45° with respect to the line between them. It may be used as a toy or for seeing over people's heads in a crowd. This form of periscope, with the addition of a simple lens, was used for observation purposes in the trenches during World War I. More complex periscopes, using prisms instead of mirrors, and providing magnification, are used on submarines.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Mirror: :This article is about the reflective surfaces. For other senses of this word, see mirror (disambiguation)....

Toy: :This article is about things that people play with. See also Toys for the 1992 film of that name starring Robin Williams; or toy dog, referring to one of many very small breeds of dog....

Prism: Prism commonly means:...

Periscope related Images and Photos (experimental)

Up Periscope (DVD)

Crewman Manning Conning Tower of US Submarine One Using Periscope During WWII