Mortars
WW1
What does it do?
It fires a projectile at a elevated angle (higher than 45 degrees) it falls from the sky and lands on your enemy.
http://efour4ever.com/granatwefer36_image.htm
https://rslvirtualwarmemorial.org.au/explore/units/452
http://nigelef.tripod.com/ammo.htm
How does it work?
Fires explosive projectiles known as (mortar) bombs at low velocities, short ranges, and high arching ballistic trajectories. Typically muzzle loading with a short often smooth barrel, generally less than 15 times its caliber.
Was it successfully used?
Yes it has been successful they have been using them for hundreds of years.