Parriss rolling-ball clock
From Object Wiki
| Parriss rolling-ball clock | |
|---|---|
 | |
| Manufacturer | (unknown) |
| Production years | 20th century |
| Production location | (unknown) |
The Parriss free pendulum clock is thus a much simplified version of the Shortt free pendulum clock in which an impulse to the pendulum is given every two seconds as compared with every thirty seconds for the Shortt pendulum.
[edit] How it works
A ‘free-pendulum’ clock which resembles the Craig clock near by in that the ‘slave’ consists of a rolling ball. In the Parriss clock, however, the ball does not deliver the impulse direct to the pendulum, but through the medium of a gravity arm, upon which it rests. The ball takes a small fraction under two seconds to complete its travel circuit. The pendulum swings freely apart from the short interval of time during which the pallet on the gravity arm rests on the small wheel mounted on an arm projecting from the pendulum, and the actual time of the impulse as this pallet falls away from the wheel.
[edit] Memories
This clock was invented by Mr E.G. Parriss, watchmaker and Jeweller. He built a purpose made triangular cabinet so that the clock could reside outside of his jewellery business in Sheringham Norfolk. From this position in the High Street it created much interest from the passing shoppers for several years. Read more at http://parrissjewellers.blogspot.com/
— Neil Oxborough
[edit] In the Science Museum's Records
Inv. No: 1959-84