The Periscope is a historical item which can be found by Emile in Neuville-Saint-Vaast during Chapter 1.
Location[]
In the trench section with a group of soldiers marching back and forth, head to the far left end then send the dog through the tunnel to collect this item.
Description[]
"To observe enemy trenches without drawing fire, officers and soldiers used periscopes, mirrors mounted in a tube that could be raised above the parapet with no risk to health."