Thomas Earnshaw (1749–1829), maker of watches and chronometers
1749 Born on 4 February at Ashton under Lyne, Lancashire.
c.1763 apprenticed to William Hughes, watchmaker, of 119 High Holborn in London
1769 married Lydia Theakston at St James' Church, Piccadilly. They had four children.
A period of itinerant work and debts followed
By 1780 he had learnt about making escapements and watch jewelling; turned his attention to improving marine timekeepers, which had been developed by John Harrison. He finalized the form of escapement (the ‘spring detent’) and the compensation balance which would be used in the standard marine chronometer thereafter. He showed his new design of escapement to friends of John Arnold and Arnold patented a variation of the idea.
Earnshaw patented his original invention through a sponsor, the watchmaker Thomas Wright.
1783 He only allowed other watchmakers to use his design if they paid a fee of 1 guinea and stamped the watch ‘Wright's Patent’.
1789 Earnshaw was introduced to Nevil Maskelyne, the Astronomer Royal, who tested an Earnshaw chronometer for six weeks and encouraged Earnshaw to continue making them. As a result, Earnshaw received orders to repair clocks at the Greenwich Observatory and was commissioned to make a regulator for the new observatory at Armagh.
1792 His master, William Hughes, died in November 1792. Earnshaw succeeded to the business at 119 High Holborn. Earnshaw then signed his work with his own name. He built chronometers to a standard plan, which led to batch production of movements by outsiderworkers.
The Board of Longitude tested his and Arnold's timekeepers; Earnshaw was awarded several prizes but the issue of priority of invention, especially about the spring detent escapement, festered for several years.
1808 Pocket chronometer on display at the World Museum, Liverpool.
c.1815 retired from running the business, handing over to his son Thomas, who continued until 1854.
1829 Died at Chenies Street, Bedford Square, London on 1 March.
Greenford Hall 
In 1801 Earnshaw moved from Kennington, London, to Greenford Hall in Greenford, Middlesex, with his four children, Manasseh William, James, Thomas and Elizabeth Ann, on the death of his wife, Lydia. The house was to be his principal residence for the rest of his life, though he did not die there. During that time, in 1805, he was awarded £3000 by the Board of Longitude, However, believing he should have received more, he wrote a long and detailed claim, but he was unsuccessful. Significantly, while he lived at Greenford Hall, he renamed it 'Longitude Hall'.
The building, known when it was a private residence as 'Greenford Hall', is much changed since Earnshaw's time, an extension having been added by Sir George Owens Thurston, a leading marine engineer about a century ago. Because of this, attempts to get it listed have been unsuccessful. As the building is the only known residence of Earnshaw to exist, this ought to be marked by a plaque, but he already has a blue plaque on the site of his business premises in Holborn.
In 1939 the building was purchased by Ealing Council and has been a community centre ever since. Due to the council's removal of its subsidy to community centres, it will cease to be a community centre in July. Its fate is unknown, but the fear is that the council will demolish the building. I, as a member of the management committee, am trying to prevent this.
As well as Earnshaw, the house was also occupied by the surgeon, politician, and founder of 'The Lancet', Thomas Wakley, and the scientist, Robert Rigg FRS
Sources of Information
- Thomas Earnshaw 2016/02/29
- Biography of Thomas Earnshaw, ODNB