Trench Warfare - Bombs Fired By Catapult (1914-1918)

Trench warfare on the Western Front during World War One. British officer standing in trench fiddling with small bomb or grenade. He strikes the bomb against a block strapped to his wrist, like striking a match, and throws it. He turns and looks at camera. A catapult is attached to edge of trench. We see a soldier pull the sling back, attaches it to a hook and puts small bomb in it. L/S of large structure in distance. Catapult is released. Seems to take some time, the bomb missing the stru