In the useful and practical arts, many inventions and contrivances, to the production of which the degree of knowledge possessed by the ancients would appear to us to have been adequate, and which seem quite obvious, are yet of late origin. The application of water, for example, to turn a mill, is a thing not known to have been accomplished at all in Greece, and is not supposed to have been attempted at Rome till in or near the age of Augustus. The production of the same effect by wind is a still later invention. It dates only in the seventh century of our era. The propulsion of the saw by any other power than that of the arm is treated as a novelty in England, so late as in the middle of the sixteenth century. The Bishop of Ely, at that time ambassador from the queen of England to the Pope, says, "he saw, at Lyons, a sawmill driven with an upright wheel, and the water that maketh it go is gathered whole into a narrow trough, which delivereth the same water to the wheels. This wheel hath a piece of timber put to the axletree end, like the handle of a _broch_ (a hand-organ), and fastened to the end of the saw, which being turned with the force of water, hoisteth up and down the saw, that it continually eateth in, and the handle of the same is kept in a rigall of wood, from swerving. Also the timber lieth, as it were, upon a ladder, which is brought by little and little to the saw with another vice."[89] From this description of the primitive power-saw, it would seem that it was probably fast only at one end, and that the broch and rigall performed the part of the arm in the common use of the handsaw. It must always have been a very considerable object for men to possess or obtain the power of raising water otherwise than by mere manual labor. Yet nothing like the common suction-pump has been found among rude nations. It has arrived at its present state only by slow and cautious steps of improvement; and, indeed, in that present state, however obvious and unattractive, it is something of an abstruse and refined invention. It was unknown in China, until Europeans visited the "Celestial Empire"; and is still unknown in other parts of Asia, beyond the pale of European settlements or the reach of European communication. The Greeks and Romans are supposed to have been ignorant of it, in the early times of their history; and it is usually said to have come from Alexandria, where physical science was much cultivated by the Greek philosophers, under the patronage of the Ptolemies. These few and scattered historical notices, Gentlemen, of important inventions, have been introduced only for the purpose of suggesting that there is much which is both curious and instructive in the history of mechanics; and that many things which to us, in our state of knowledge, seem so obvious as that we should think they would at once force themselves on men's adoption, have, nevertheless, been accomplished slowly and by painful efforts.