Derek Roberts, English Precision Pendulum Clocks, Schiffer, 2003, pp. 83-93, figs. 16-17A-E
William Hardy was a Scotsman who is believed to have arrived in London in about 1800, settled in 29 Coldbath Square, Farringdon, near Clerkenwell and set himself up as a watch and chronometer maker. He made various presentations to the Society of Arts including one on 'a compensating balance' and another on 'the arcs of vibrations in timekeepers'. Hardy was certainly a very fine craftsman; a chronometer by him was noted by a sea captain, William Brown, as having been taken on a voyage from Liverpool to Cape de Verd on the coast of Africa. He discovered it had varied by no more than one second.
However, Hardy was not to be remembered for his watch or chronometry skills but for the spring-pallet escapement which he invented and presented in a paper to the Society of Arts in 1807 (for which he won a Gold Medal and £50). He first fitted it to a regulator movement by another clockmaker which had deadbeat pallets. He found his escapement performed so well that he wrote to the Board of Longitude who referred the matter to the Astronomer Royal, the Reverend Dr. Maskelyne. Maskelyne tested the clock thoroughly and found that from 27 May to 27 August the clock remained within the same second. Hardy was asked to make another for the Circle Room at Greenwich, no cost to be spared. He took Maskelyne for his word, made the clock and sent a bill for £325, a sum that the Council of the Royal Society decided was too much and after much deliberation Hardy received £200.
The performance of Hardy's regulator was sensational, being over three times more accurate than the one by Graham which it replaced. Orders come flying in from observatories such as Cape Town, Wilno Observatory, Poland and the Cambridge Observatory (now the Whipple Museum and still with the original pallets). In all it was thought that perhaps 28 were made, 18 of which are currently recorded.
A regulator by Hardy was delivered to the Royal Military Academy in about 1819. It is interesting to note that West Point, the American Officers' Military Academy, had already ordered one in 1812. The Military Academy at Sandhurst had built an observatory in the grounds because it was considered that astronomy should be part of every officer's education. Maps from the early 19th Century of the Academy and its grounds clearly show the observatory on a hill to the north east of the college and due east of the stable yard. The provenance for this clock cannot be established beyond doubt but it would appear that when the observatory was no longer being used the Academy sold the regulator in about 1870 to Charles Borelli, a clockmaker who was then at Aldershot. The family were silversmiths to George VI and had responsibility for the upkeep of the clocks at Windsor. By the time they closed down, the business had been moved to Farnham. The contents of the showroom and workshop were bought by Evans & Evans and the regulator was subsequently bought, restored and sold to the present owner. The restoration was carried out by Roger Stevenson using Hardy's original drawings and also the measurements from the clocks at Greenwich, and Cambridge.