The conning-tower and periscope are placed on the upper deck, as shown.
I was glad when I picked up its homely white front in my periscope.
The captain turns the periscope around, scanning the waters.
This periscope was not in use and had not been above the surface.
He looked neither to right nor left but was still at the periscope.
De Hooch went over to the periscope and put his eyes to the binoculars.
There was one who called it a dull watch when he did not see at least one periscope.
He had never seen a periscope in his life, but he had read about periscopes.
In sticking out the periscope, lookouts on ships are likely to see it.
He was one day on the bridge of his ship when the lookout shouted: "Periscope!"