Escapement each time it filled up, thus advancing the clock's wheels each time an equal quantity of water was measured out. The time between releases depended on the rate of flow, which decreased with water pressure as the level of water in the source container dropped. The development of mechanical clocks depended on the invention of an escapement which would allow a clock's movement to be controlled by an oscillating weight. Unlike the continuous flow of water in the Chinese device, the medieval escapement was characterized by a regular, repeating sequence of discrete actions and the capability of self-reversing action: Both
Escapement 'anchor' pallet locks the larger wheel and, on this being unlocked, a pallet on the end of the lever is given an impulse by the smaller wheel through the lever fork. The return stroke is 'dead', with the 'anchor' pallets serving only to lock and unlock, impulse being given in one direction through the single lever pallet. As with the duplex, the locking wheel is larger in order to reduce pressure and thus friction. The Daniels escapement, however, achieves a double impulse with passive lever pallets serving only to lock and unlock the larger wheel. On one side, impulse is