Water was the main source of mechanicalpower, and by the end of the seventeenth century, England alone is thought to have had some 20,000 working mills.
水是机械动力的主要来源，而到了17世纪末，人们认为仅英格兰就有2万个左右的工作磨坊。
2
Great Britain had large amounts of coal; however, there were not yet efficient means by which to produce mechanical energy or to power machinery.
英国有大量的煤；然而，当时还没有有效的方法来产生机械能或为机器提供动力。
3
William measured the mechanicalpower of the mechanism. He thought that chould be done by mean of electricity.