The 3-inch mortar was one of the most effective battalion weapons, used for medium and long range support and bombardment on the battlefield. It has served the British Army in various forms (it is now the 81mm Mortar) for many decades. It delivers a high explosive charge at high angle, allowing it to be effective against troops on the ground, troops in trenches, and to bring fire behind intervening obstacles such as buildings, trees and hills. The pamphlet gives full details of the weapon including the mounting, base plate and sights. The working stores are listed and there is a substantial examination of ammunition and fuses. Four plates show the weapon assembled, the mounting, the sights and the bomb.