The extensive use of manpower and animal power in pre-industrial societies has been described in previous chapters. The wind, driving ships across the waters, was probably the first non-muscular source of power but it took about four millennia, from before 3000 B.C. to about 1000 A.D., for it to be transferred to power generation on land. In the meantime machinery driven by waterpower was invented and developed and wind power, when it was applied on land, was preferred only where water was unavailable.
The development of waterpower from its invention in the Roman era is oudined in this chapter. The earliest mills were vertical-axis machines used to drive millstones, and were followed by horizontalaxis machines that were also used mainly to grind flour. In the Middle Ages other applications for water power were found, for example, to saw logs, to operate bellows supplying air to furnaces, to drive fulling mills, to pump water either to irrigate or drain the land or to drain mines, and to operate stamps to crush the mined ore. The chapter concludes with an analysis of the power output, efficiency, and speed of horizontal-axis machines used in undershot and overshot applications, and of horizontal-axis impulse machines.
The earliest known mention of a water mill seems to be in a short poem by Antipater of Thessalonica in about 85 B.C. Various translations have been made but the most literal and practical translation is that of Beckman quoted in Bennett and Elton (1898, 2, 6). “Cease your work, you who laboured at the mill. Sleep now and let the birds sing to the ruddy morn. Mother-Earth has commanded the water nymphs to perform your task; and these, obedient to her call, throw themselves on the wheel, force round the axle-tree, and so