All ready to "go in" (I.e. to the trenches)

Gas mask as worn during gas attack. It might have to be worn this way for hours. The eyepieces were treated with a special grease to prevent blurring. The Germans had an eyepiece which would fog on one side owing to its material.

BC Archives, MS-2879 Box 83 File 1 / CREASE FAMILY / “Diary of the War”, diary and scrapbook of Arthur Douglas Crease, 1915-1919.