PERISCOPE • E-FREE TRANSLATION.COM • Definition of Periscope

... hard filbert nuts were being cracked by giant teeth. Each time I went there one of our men was hit by a sniper, and his body was carried off for burial as I went toward the first line of trenches, hoping that my shadow would not fall across a German periscope. The sight of that dead body passing chilled one a little. There were many graves in the bosky arbors—eighteen under one mound—but some of those who had fallen six months before still lay where the ...

— Now It Can Be Told • Philip Gibbs

... rang out. It came from the window. The tinkle of broken glass sliding down the bamboo tube told that the periscope was a wreck. ...

— Panther Eye • Roy J. Snell