Soldiers taking part in artillery exercise on firing range.
SLATE INFORMATION: Uncle Sam's Newest Guns roar Defiance to 'Invading Planes'
US soldiers aiming anti-aircraft guns at sky
Aeroplane flying overhead
Artillerymen aiming guns
General Charles P Summerall (Chief of Staff) aiming high-angle machine gun
Rapid firing three inch artillery firing
Explosions in sky
Soldiers loading and firing artillery
Smoke in sky
More of guns being fired
Large artillery being fired
Background: Soldiers taking part in artillery exercise on firing range.