Periscope
Underwater viewing tube
A periscope is an optical instrument that uses mirrors or prisms to allow viewing of objects not in a direct line of sight.
The classic design features a tube with angled mirrors at each end, enabling someone in a lower position to see over or around obstacles.
Submarines use periscopes to observe the surface while remaining submerged; soldiers in trenches used them to peer over walls without exposing themselves to enemy fire.
Through the periscope, the captain spotted the enemy vessel.
Light-focusing curved glass
- mirrorReflective viewing surface
- prismLight-splitting optical element
- reflectionReturned light or thought
- tubeHollow cylindrical passage
eyepiece · magnification · optics · viewfinder · angled · cylinder · rotating · housing
Submarine's raised control structure
- U-boatUndersea warship from Germany
- underwaterBelow the surface
- submergedBelow water's surface
- surfaceOutermost boundary layer
sonar · torpedo · naval · captain · hatch · vessel · warfare · dive
Secretly observing others
- observationAttentive watching or remark
- concealmentAct of hiding something
- watchingActively looking at something
- reconnaissanceInformation-gathering before action
peek · hidden · covert · lookout · trench · above · sightline · monitoring
lens
Light-focusing curved glass
- mirrorReflective viewing surface
- prismLight-splitting optical element
- reflectionReturned light or thought
tube · eyepiece · magnification · optics · viewfinder · angled · cylinder · rotating · housing · field of view
conning tower
Submarine's raised control structure
- U-boatUndersea warship from Germany
- underwaterBelow the surface
- submergedBelow water's surface
surface · sonar · torpedo · naval · captain · hatch · vessel · warfare · dive · observation
spying
Secretly observing others
- observationAttentive watching or remark
- concealmentAct of hiding something
- watchingActively looking at something
reconnaissance · peek · hidden · covert · lookout · trench · above · sightline · monitoring · undetected
Microblogging social network
- livestreamReal-time internet broadcast
- broadcastTransmitted media signal
- videoRecorded moving imagery
streaming · live · social media · followers · hearts · viewers · mobile · real-time · comments · notification
cardboard
Rigid paper for containers
mirrors · homemade · plastic · play · educational · children · simple · makeshift · experiment · build
- social mediaposts, post, influencer status, followers, tweet
- defunct techAIM, GeoCities, Google+, Myspace, Napster
- live feedswebcam, traffic cam, security cam, CCTV, dash cam
- Analytics ToolsTableau, Looker, Google Analytics, Jasper, dashboards
- obsolete techfloppy disk, VHS, dial-up modem, cassette tape, floppy disks
Periscopeobservation tower
Elevated structure for viewing
watchtower · crow's nest · lookout post · observation deck · elevated platform