This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Muzzle of German cm gun Chuignes AWM E. AWM caption France Picardie Somme Chuignes hass adfa edu au pid Lieutenant Cecil Olbers Clark MM MC rd Battalion holds six inch ruler to the muzzle of destroyed German sic actually inch naval gun to give an indication of the weapon's calibre The barrel has been packed with mud or concrete