WW1 1914 4.5 Q.F. Mark 1 Howitzer Gun Range Slide Rule With Hand Written Factors 7x2 inches. Made by Raphael's London 1914. Used in famous WW1 Battles to calculate firing parameters by officers for 4.5 inch QF Howitzers. Small scratch as shown in photos. This example has hand written factors on the reverse of the rule to aid in rapid calculations by the user. This is an important insight into how light cannons were fired in famous WW1 battles. A very rare surviving unique item.
