FROM the earliest days of the hobby, model engineers have been fascinated by the Congreve clock. When the hobby was in its heyday you could expect to see at least one at any large show. So it was a great pleasure to see a very nice Congreve clock at Sandown Park after an interval of some years. It was made by SMEE member Adrian Garner and, as can been seen, presented in a most attractive case.

Designs for amateurs to build by Dr Bradbury Winter and John Wilding have been available for some time. John has also made one from Meccano which he tells us is more a more accurate timekeeper than the conventional version.

The interest in these clocks is in watching them in motion rather than as a means of keeping time. You can guarantee that anyone passing a working Congreve will stop, and have a smile on their face. Unfortunately, it is impossible to keep time better than about 15 minutes a day. But as a piece of ‘craftsman’s art’ it is superb.

The clock, which uses a rolling ball and tipping platform rather than a clock type escapement,

was patented by Sir William Congreve in 1808. He was a prolific inventor.

Congreve’s clock may not be rocket science but  he was a pioneer of rocket artillery, and was Comptroller of the Royal Laboratories at Woolwich Arsenal. Congreve Rockets were used against the French fleet in the Napoleonic wars, and are the “rocket’s red glare” of the American national anthem.

He was responsible for a whole range of other inventions, was a Member of Parliament, and a Fellow of the Royal Society. So much more to him than inventor of an unusual clock.

In action, the ball typically takes 15 seconds to run down the zig-zag track, where it trips the escapement which, in turn, reverses the tilt of the tray and at the same time makes the hands of the clock move forward. The plate then reverses. The second hand jumps forward 15 seconds on each oscillation.

Adrian’s clock is shown above. Below is a clock from 1820 in the British Museum - Photograph by Dr Mike Peel, who is an astrophysicist rather than a rocket scientist! (www.mikepeel.net)