William Simms (1793-1860)
He was an excellent craftsman and business, who had an instrument-making business in Aldersgate Street.
1828 William Simms, Fleet Street, Astronomical Instrument Maker, became a member of the Institution of Civil Engineers.
1861 Obituary 
William Simms was born on the 7th of December, 1793, at Birmingham, whence he was shortly afterwards brought to London by his parents, by whom he was apprenticed to Mr. Bennett, a mathematical instrument maker of considerable ability and reputation.
At the expiration of his apprenticeship, he commenced business on his own account and shortly afterwards, becoming a Member of the Society of Arts, he made the acquaintance of the late Bryan Donkin and Francis Baily, who introduced him to Colonel Colby, the then Director of the Ordnance Survey, for which branch of the public service, he was intrusted with the construction of a great number of theodolites.
In 1826, he entered into partnership with the late Edward Troughton, on whose retirement, at the end of seven years, he became sole proprietor of the business in Fleet Street, which enjoyed such high and deserved reputation, for the accuracy of the instruments manufactured at that establishment.
In 1828, he became an Associate of the Institution, and during many years he was a constant attendant at the meetings.
In 1834, he delivered, at the request of the then President, Mr. Telford, a lecture on the Edinburgh Mural Circle, which he had just completed, and upon the subject of Graduating Astronomical Instruments.
He constructed instruments for many foreign observatories; and the Royal Observatory at Greenwich contains several specimens of his skillful workmanship, particularly the optical part and the graduation of the transit circle, the altazimuth instrument, &c. The Cambridge mural circle was also constructed by him.
He made great improvements in the art of graduating instruments, and by his self-acting circular dividing engine, he reduced the labour of weeks to that of a few hours.
He communicated to the Royal Astronomical Society, of which he became a Fellow in 1831, a detailed account of this instrument, (with which the above transit circle, and the zenith sector of the Ordnance Survey were graduated,) which was published in their Memoirs.
He took part in the experiments for determining the true imperial standard yard, and also in its construction.
In 1852, he was elected a Fellow of the Royal Society.
He died at his residence, Carshalton, Surrey, on the 21st of June, 1860, in the sixty-seventh year of his age, highly esteemed for the quiet courtesy and the truthful disposition which he had ever displayed throughout his life.