While many of al-Jazari's inventions may now appear to be trivial, the most significant aspect of al-Jazari's machines are the mechanisms, components, ideas, methods, and design features which they employ [REF].
A camshaft, a shaft to which cams are attached, was introduced in 1206 by al-Jazari, who employed them in his automata,[REF] water clocks (such as the candle clock)[REF] and water-raising machines [REF].