Periscope
Overview
A periscope is an optical instrument that allows observation from a concealed or protected position. This device is most commonly associated with submarine warfare, enabling the crew to observe the surface of the water and the surrounding environment while remaining submerged.
History
The concept of the periscope, while not named as such, has roots in ancient times. The earliest known practical telescopic periscope was invented by Johannes Hevelius, a 17th-century Polish astronomer. However, the modern periscope, complete with prisms and a telescopic view, was developed in the 19th century.
Design and Function
A periscope operates on the principle of reflection of light. It consists of a long tube with mirrors or prisms mounted at each end at a 45-degree angle. The top mirror captures the image from outside and reflects it down the tube to the bottom mirror, which then reflects the image to the viewer's eye.
Types of Periscopes
There are two main types of periscopes: the conventional periscope and the non-penetrating periscope. The conventional periscope is the type most commonly associated with submarines, while the non-penetrating periscope is a more modern design that uses fiber optic technology to relay images.
Applications
While periscopes are most commonly associated with submarines, they have a variety of other applications. They are used in tank warfare, allowing the crew to observe the battlefield while remaining protected inside the tank. In civilian applications, periscopes are used in certain types of cameras, in building construction, and even in some models of cars to improve driver visibility.