Lot Essay
Sir William Congreve Bt. 1772-1823, was a colourful gentleman scientist whose principle invention was the Congreve Rocket, a missile used heavily during the Napoleonic wars. Congreve inherited his title in 1814 and was already a Fellow of the Royal Society and Member of Parliament. Succeeding his father as Comptroller of the Royal Laboratory put him closer to the attention of the King who it seems took an interest in Congreve's horological inventions to the extent that two of Congreve's clocks remain in the Royal collection to this day.
The present example is one of only two examples of this construction bearing the Royal coat of arms. The signature plate refers to the patent for an extreme detatched escapement which Congreve took out in 1808. The idea behind the patent was to remove any variation or fluctuation caused by the escapement to the isochronism of the pendulum. The patent reads as follows;
A light spring wheel of thirty teeth is unconnected with anything but the seconds hand and a pair of pallets. Another pallet on the same stock is connected to a large wheel with sixty teeth. On the face of this wheel are sixty pins and a lever acting on these locks the wheel. On the face of the little wheel is one pin. A seconds pendulum being set in motion, the pallets drive the little wheel, and, at the sixtieth second, the pin discharges the lever from the pins of the large wheel, this, being thus unlocked, starts foward from the action of the first mover, and one of its teeth striking the pallet of the large wheel, gives motion to the pendulum. When the pin on the little wheel has passed the lever, the lever re-locks the large wheel for another fifty nine seconds
The present example is one of only two examples of this construction bearing the Royal coat of arms. The signature plate refers to the patent for an extreme detatched escapement which Congreve took out in 1808. The idea behind the patent was to remove any variation or fluctuation caused by the escapement to the isochronism of the pendulum. The patent reads as follows;
A light spring wheel of thirty teeth is unconnected with anything but the seconds hand and a pair of pallets. Another pallet on the same stock is connected to a large wheel with sixty teeth. On the face of this wheel are sixty pins and a lever acting on these locks the wheel. On the face of the little wheel is one pin. A seconds pendulum being set in motion, the pallets drive the little wheel, and, at the sixtieth second, the pin discharges the lever from the pins of the large wheel, this, being thus unlocked, starts foward from the action of the first mover, and one of its teeth striking the pallet of the large wheel, gives motion to the pendulum. When the pin on the little wheel has passed the lever, the lever re-locks the large wheel for another fifty nine seconds