Apparatus Named After Our Academic Ancestors - V

In the museum wing of the Greenslade house is a clock with a two-second pendulum about one meter long (Fig. 1). This ticks once per second, and every time it passes through dead center it completes an electrical circuit. When I came to Kenyon in 1964, this system was used to send signals to a series of telegraph relays, which ticked once per second. Students in the first-year laboratory used beats between the ticking sec-onds and the oscillation of the pendula they were studying in an era when stopwatches were expensive. This clock inspired me to write this article about physicists who have pendula named after them: Christiaan Huygens, Lionel Wilberforce, Henry Kater, Benjamin Robins, Leon Foucault, and Hugh Blackburn.