One last odd weapon, this from Popular Science, September 1917: Enid S. Wales of Detroit proposed a shell that would spread coils of barbed wire before an onrushing enemy, stopping their progress and exposing them to attack by infantry and machine guns.

Four hollow caps containing coils of barbed wire would be fitted to a trench mortar shell, one end of each coil secured to the body of the shell. “When the projectile explodes, the caps containing the barbed wire shoot out like bullets in all directions distributing the wire in great tangled masses.”

I don’t know if the idea was ever put into practice.