Early balloon-defence guns and awkward mountings

The Royal Navy experimented with the 3-pounder and quick-firing 1-pounder before the 2-pounder pom-pom arrived in 1915. German balloon-defence guns originated in the 1870s as a way to intercept message balloons leaving besieged Paris. The original weapon remained a standard German anti-aircraft gun some 30 or 40 years later. These weapons remained primitive: fire depended on visual judgment, and one illustrated shipboard mounting stood on wheels on the deck. A loading example required the gun to return to the horizontal so the shell could be matched to the rifling grooves. A useful anti-aircraft weapon also needed a practical mounting and a workable loading cycle at high elevation.