- Siege Engine
The application of mechanical power enables Cities to build Mills. They improve City Production. Mechanical advantage can also be applied to warfare to build Siege Engines to attack fortifications and fortified cities.
Muscles, either of people or animals, have powered all human endeavors throughout most of human existence. The first addition to this power was the use of windmills by the Babylonians around 1700 BC to pump water into irrigation canals. 1500 years later the horizontal waterwheel was invented in Armenia to harness the force of moving water to grind grain.. In 1 AD Vitruvius described an undershot waterwheel in use by the Romans that achieved an efficiency in converting the force of the water into useful work of about 15 - 30%. Soon afterwards waterwheels were in use in China to drive bellows for blast furnaces smelting cast iron. By the late Empire, the Romans were building batteries of up to a dozen waterwheels on large streams and rivers to power grinding machines that could provide flour for entire cities. The Romans never applied waterpower to anything beyond milling grain and raising water, however. The vast extension of waterpower and wind power occurred in the Middle Ages. Waterwheels were built to use either overshot or undershot water, and proliferated in the 10th century, used not only to grind grain but also to power saws, looms, and other primitive manufacturing processes. The vertical windmill was invented late in the 12th century AD, probably in East Anglia, England, and this power source was also applied to a wide variety of industrial and food production work. By substituting relatively cheap water and wind power for expensive animal or human muscle, the numerous water and windmills made many products both cheaper and more common, fueling a ’mini-industrial revolution’ in medieval Europe.