Peter John Margary was born 2 June 1820 in Kensington, London. In 1838 he was articled to William Gravatt and was then Brunel’s chief assistant on the Bristol and Exeter Railway, he was then appointed assistant to William Froude. Margary worked for the South Devon Railway to supervise the Exeter-Powderham contract and then from July 1845 he was put in charge of the construction of the atmospheric engine houses. He became the South Devon Railway’s Resident Engineer and on Brunel’s death in 1859 he became Engineer of the Railway. At this time he lived in Charlton Villa, Park Hill (now Strand Hill) Dawlish, his office appears to be in his house. In 1860 Margary was appointed additionally as Engineer of the Cornwall and West Cornwall Railways and moved to Plymouth. He was responsible for building the Launceston, Moretonhampstead, Ashburton and St Ives branches. The GWR took over the railway in 1876 and Margary became Divisional Engineer, Western Division. In this role he was responsible for the first Cornish viaduct reconstructions. He retired in 1891 and died in London on 29 April 1896.