Periscope

A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current 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 armoured vehicles.

More complex periscopes, using prisms and/or advanced fiber optics instead of mirrors, and providing magnification, operate on submarines and in various fields of science. 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.

Early examples

Johannes Gutenberg, known for his contribution to printing technology, marketed a kind of periscope in the 1430s to enable pilgrims to see over the heads of the crowd at the vigintennial religious festival at Aachen. Johannes Hevelius described an early periscope with lenses in 1647 in his work Selenographia, sive Lunae descriptio [Selenography, or an account of the Moon]. Hevelius saw military applications for his invention.

Periscope (album)

Periscope is the third studio album by the stoner rock/psychedelic rock band Colour Haze, released in 1999.Periscope was re-released in 2005 on the label Elektrohasch, which featured the bonus track "Transmitter" not previously included on the 1999 version.

Track listing

References

Periscope (arcade game)

Periscope (ペリスコープ) is an arcade game released in Japan by Sega Enterprise in 1966. The game was developed by the newly-merged Sega Enterprise's CEO, David Rosen.

Play

The game was electro-mechanical in the era prior to true video games. It consisted of a backdrop representing the ocean, where cardboard cutouts of ships were moved horizontally on chains. In front of this was a horizontal board with a grid of lights that represented the torpedoes moving towards the ships in side-scrolling fashion. The game was played looking through a simulated submarine periscope that limited the field of view so the horizontal and vertical playfields appeared almost continuous. Due to the relatively large horizontal surface, and the machinery behind the vertical surface, the game cabinet was very deep, two to three times the depth of a conventional arcade game.

Reception

The game encountered great success in Japan, and was released in the United States the following year. The game found further success in the US and in Europe. Rosen later described the game as being considered by experts in the community as "turning point in the industry."