Double Bell Alarm Clock - Memory Lane: 15 Household Items From Your Childhood That New Houses Will Never See - Bob Vila
Double-Bell Alarm Clock
A traditional windup alarm clock is completely mechanical, driven by springs. The double-bell model has a gear-driven hammer that oscillates back and forth between the bells to wake you at the time you set it to go off. As an added benefit, the clock's monotonous tick-tick-tick might just put you to sleep at night.