One of the most important aspects of warfare during the First World War was the artillery. Responsible for an estimated 60 per cent of all casualties on the Western Front, the artillery began the war woefully unprepared for what would become a complex task of counter-battery work and intricately moving barrage fire.
Perhaps surprisingly, the artillery was not prepared to hit targets the gunners could not see. Pre-war expectations revolved around artillery pieces being wheeled into line with the infantry, but it quickly became apparent this gave the enemy a clear shot, and so guns were pulled back out of sight to avoid the destruction of each side’s artillery.
This created a mass of problems in effectively directing artillery fire. In order to see where shells were landing, observation officers climbed something high – a tree, building, pole, or hill – and shouted information down to the gunners. The process was eventually streamlined into one observer per battery instead of one observer per gun (with an attending circus of observers in a nearby tree). Eventually the air service became involved, passing on information about the flight of shells.