First World War (1914-1918)
The U-Boat Menace

The emergence of the submarine was a major development in naval warfare. German submarine - or U-Boat - attacks against Allied shipping in the Atlantic and in European waters posed a major threat to the Allied war effort.

Periscope Lens, U-117

This lens is part of the periscope that allowed U-Boats to see what was happening on or above the water.

After sinking more than 20 ships during the last year of the war, U-117 surrendered at Harwich, England after the November 1918 armistice. A.R.M. Lower, a Canadian officer in the Royal Navy and later a prominent Canadian historian, once owned the lens.

Periscope Lens
CWM 19740259-010