"Shell are made of cast iron... and are sent flying toward the enemy camp from an eruptor."
Jiao Yu and Liu Ji, Fire Dragon Manual(c. 1368-1398)
During the Chinese Song Dynasty (circa 960-1279), artillery engineering exploded, as it were, with the development of the ancestor of the cannon: flame- throwing "fire lances" made of bamboo. When gunpowder at one end was ignited, it forced sand, lead pellets, or shards of pottery at the enemy. When metal later replaced bamboo, probably in the early 1100s, these lances became "fire tubes" or "eruptors." The oldest record of them is a painting, dated to 1128. The early Chinese cannons could throw a ball about 50 yards (45 m). A century later they had become powerful enough to breach city walls, and were made of bronze. According to the historian of Chinese technology Joseph Needham, cannon warfare took a great step forward with the development of cannonballs that fitted the tube's bore precisely, enabling more control. Later cannons were made of cast iron, and some were wheeled.
Cannon technology spread and was developed in Europe; the Scots defended Stirling Castle with cannons in 1341, and three cannons were used at the battle of Crecy-en-Ponthieu in 1346 by England's King Edward III, who nad more than a hundred of them in London. Such early European cannons were small, but by the end of the Hundred Years' War (1337-1453) giant ones were available, known as "bombards." Mons Meg, a bombard built in 1457, survives at Edinburgh Castle in Scotland; with a 22-inch (56 cm) caliber barrel, it is capable of firing gunstones weighing 331 pounds (150 kg) nearly 2 miles (3.2 km).
From the sixteenth century, lighter cannons capable of more accurate fire were developed, and these gradually evolved into modern artillery pieces, such as the howitzer used to great effect in the American Civil War (1861-1865).
