It is seldom possible to determine exactly when a particular mechanical device was discovered or invented, but in general the chronological development was as follows. The principle of the lever was certainly known as early as the Upper Paleolithic Age, when it was employed in such composite tools as the spear-thrower; at the same time the concept of rotary power is evident in the use of the bow drill. The lever, the inclined plane or wedge, and the cylindrical roller were all used to great advantage by the Egyptians in the construction of their pyramids at the beginning of the Bronze Age. The lever was later to be applied to other devices, such as the beam-press of the classical period. With the invention of the pulley came two important advantages: the ability to change the direction of a force, and the multiplying of the available power. The pulley, together with its attendant devices such as the windlass, is not mentioned in literature until the fourth century B.C.E., but it was certainly used much earlier: even the Egyptians had discovered the usefulness of changing the direction of a force by passing a rope over a fixed horizontal bar, but it remained for the Greeks to devise a pulley system that increased mechanical advantage as well; and we credit the Greek scientist Archimedes with the invention of the compound pulley. We are told, perhaps with some justification, that it was Archimedes, too, who, in the Hellenistic period (late third century B.C.E.), applied the concept of the screw (really just an inclined plane wrapped around a shaft) to practical uses like the raising of water and crushing of olives. He is also credited with the invention of the toothed gear, a revolutionary device that could change the direction of power and increase or decrease the speed of movement. (Source: Ancient Technology).
Ancient Technological Vision
