308. A detached pendulum escapement, leaving the pendulum, P, free or detached from the escape-wheel, except at the time of receiving the impulse and unlocking the wheel. There is but one pallet, I, which receives impulse only during the vibrations of the pendulum to the left. The lever, Q, locks the escape-wheel until just before the time for giving the impulse, when it is unlocked by the click, C, attached to the pendulum. As the pendulum returns to the right, the click, which oscillates on a pivot, will be pushed aside by the lever.