What is a periscope and waht is its use?
A periscope is an instrument 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 World War I. Military personnel also use periscopes in some gun turrets and in armored vehicles.
More complex periscopes, using prisms instead of mirrors, and providing magnification, operate on submarines. The overall design of the classical submarine periscope is very simple: two telescopes pointed into each other. If the two telescopes have different individual magnification, the difference between them causes an overall magnification or reduction.
uses of Periscopes
A periscope is a instrument of observation used for naval use or for other war-like purposes. In fact the first periscope prototype was made by Johann Gutenberg which was used to enable people to see over the heads of the crowd at the Vigintennial religious festival at Aachen. In the navy it is used in submarines to view possible threats such as enemy submarines or sea mines. Marie Davey built the first naval periscope, a simple, fixed periscope using mirrors in 1854. 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 person's eye.
A periscope is an optical device which allows an observer to see things which are beyond his or her line of sight. One of the classical uses of a periscope is in submarines. Instead of needing to surface to see what is going on at sea level, the submarine can instead stay safely submerged under the water and extend a periscope to look around. Periscopes are widely used in the military, but also in other fields, such as medicine and hunting.
Several crude versions of the periscope were used as far back as the 1400s, but the modern design was developed in the late 1800s, when the obvious military applications of the periscope began to be realized. By World War One, periscopes were standard issue to many troops in the trenches, and they were also utilized in submarine warfare.
Periscopes consist of a long tube which contains either mirrors or prisms. The mirror or prism at one end captures the image and bends or reflects it so that it can travel down the tube to hit the mirror or prism at the other side, bending the image again so that it can meet the eye of the viewer. If the tube is extremely long, magnifying glasses may be used to enlarge it so that the viewer can see clearly. Periscopes can be portable, as in the case of the trench periscopes used in the First World War, or they can be fixed into a housing such as a tank or submarine.