German WWI RPC, Armed Garde Artillerymen, Reichs Revolvers 1914

Original period photography. Clear, full length image of two Prussian Garde Artillerymen, each wearing a M1893 Reichs Revolver on his belt. Cradled in their arms are photographers prop artillery projectiles. At  their feet is a shield which proclaims in German, 'The Thunder of Cannon Is Our Greeting'. Period letter on the reverse with a 10 August 1914 cancellation. Looking at these two men I wonder how they fared in the next 4 years.