Artillery. Roman Catapult. Before gunpowder was invented mechanical throwers were extensively employed. Engines invented by cunning men to shoot arrows and great stones are mentioned in the Old Testament; and catapults; balistas and similar weapons were used by the Greeks and Romans and by mediaeval armies until the introduction of cannon in the 14th century. Fifteen-inch Howitzer. Howitzers played a very important part in the Great War of 1914-1918; and were used by all the armies for bombardment of entrenched positions. By the end of the war the British armies had 6;437 howitzers of various calibres in France alone; the heaviest being the fifteen-inch howitzer illustrated. Illustration for one of a set of cigarette cards on the subject of Past & Present issued by Wills in 1929.