ABSTRACT
There are a few inventions which have the character of quite new departures, since not only do they greatly diminish labour, but they perform, by mechanical contrivances, operations which had been supposed to be beyond the power of machinery to execute. In 1843 Mr John Ridley, a miller of Durham, who had emigrated to South Australia in 1840, invented a machine for stripping off the ears of the wheat and separating the grain, so that it was at once ready for market. In the great wheat-fields of California and Australia, with an almost uniformly dry climate at harvest time, it is this saving of labour which is the chief consideration. The natural sources of power known to and utilised by the ancients were two only, wind and running water. Water-mills were known to the Romans in the time of Julius Caesar, and they were used either for raising water for irrigation, or for grinding corn.
