Assertion: periscope | /r/ObjectUse | used in submarine
Facets:
value: for aligning the submarine
type: PURPOSE
Source sentences:
text: The following requirements are for periscopes which have been used in submarines: field, at least 40 degrees to 45 degrees; magnification, between 1.2x and 1.5x; exit pupil, at least 5 millimeters in diameter; length, not specified; external diameter, 5 inches; thickness of walls, about 1/4 inch.
text: This simple periscope uses only flat mirrors as compared to the periscopes used on submarines, which are usually a complex optical system using both lenses and mirrors.
text: A periscope is a mirror-filled tube used by submarines, but that’s not what we’re talking about.
text: The periscopes are used to observe over the obstacles of between 9 and 26 meters in height, and they are used in the submarines in general observation of submerged navigation, and for correctly aligning the submarine when firing a torpedo at a target.
text: The simple periscope in Figure 1 uses only flat mirrors as compared to the periscopes used on submarines, which are usually a complex optical system using both lenses and mirrors.