William Gravatt

William Gravatt FRS (14 July 1806 – 30 May 1866), was an English civil engineer and scientific instrument maker. At age 15, his father negotiated an apprenticeship to mechanical engineer Bryan Donkin. During this period he met and became friends with John Smeaton, Edward Troughton and Dr. George Wollaston.

Career Gravatt joined the Institution of Civil Engineers as an Associate in 1826, and in 1828 was elected a member, In 1832 he became a FelIow of the Royal Society, and a Fellow of the Royal Astronomical Society.

Thames Tunnel

Before he finished his apprenticeship, Gravatt successfully interviewed with Sir Marc Isambard Brunel, and was given a job as a supervisor on the Thames Tunnel. He was replaced by William Bull.

In 1834, he was employed by Brunel on a number of works. His major project was to survey the Taff Vale Railway, from Cardiff to Merthyr Tydfil and onwards to Dowlais. He was also asked to design several bridges for both the mainline and extensions to the Great Western Railway. Brunel himself was in charge of the design of White Ball Tunnel. Through having from the outset deployed his own "curve of sines" mathematical theorem in his original surveys, the final laid operational lines did not deviate from the original drawings by more than . In mid 1841, Brunel revealed to the shareholders that he was about to dismiss his entire northern engineering team, although Froude was the son of major B&ER shareholder R.H. Froude, the Archdeacon of Totnes. Brunel wrote to Gravatt on 18 June 1841 stating that he had lost confidence in him, forcing his resignation; he was replaced by John Joseph Macdonnell. The Bristol to Bridgwater section of the B&ER was opened to traffic on 14 June 1841, and on 30 June through running on the GWR between London and Bristol began.

Gravatt subsequently resurrected his reputation by designing and being appointed superintended for the St. Philip's drawbridge, Bristol, But post this period, although appointed Chief engineer on a number of proposed railway projects during the early Railway Mania period of 1845–6, as an investor he lost a great deal of money when many were never constructed.

The eventual Craig telescope was the largest refracting telescope (a telescope with a lens) in the world from 1852. It quickly fell into disuse, and was dismantled in 1857.

Difference engine

When Per Georg Scheutz brought his Difference engine to London in 1854, Gravatt engaged its inventor in conversation. His knowledge allowed Gravatt to commission a copy from Donkin, which was sent to Somerset House. From 1855 he gave lectures on the machine to professional audiences, including the Royal Society attended by Prince Albert, and followed this with lectures at the International Exposition in Paris. Gravatt then worked with the Registrar-General to establish public faith in the machine, by quickly calculating specimens of logarithmic and other tables. He died at his home, 15 Park Street, Westminster on 30 May 1866, aged 59. A later coroner's inquest cleared her of any cause in Gravatt's death, recording a cause of accidental death.