Victorian illustration to download showing a group of soldiers demonstrating a heavy gun with a revolving turret. In the background is a pile of cannon balls. This was Moncrieff’s Protected Barbette gun invented by Captain Moncrieff in the 1860s. This gun had a revolving turret and an apparatus for raising the gun to fire and lowering it to load, thus protecting the soldiers behind the parapet and allowing lateral movement to the gun. Previously guns were fired through embrasures in the parapet, which limited their movement.