ocr: WATER WHEEL Water hitting the paddles on the rim ofa water wheel produces a strong driving force on the central shaft. The first water wheels, built by the Greeks in the first century BC, were horizontal. These were later replacedby vertical water wheels, which could be built to a larger size, generating more power. PADDLES CENTRAL SHAFT
(.png)
(Dorling Kindersley).iso/article3/turh/turh0z.dib/turh0z.png)