George Marshall Callender
1859 William Ormiston Callender (1827–1908), a commission merchant, and his wife, Jean, née Marshall, the daughter of a Greenock tanner and their family moved to Hammersmith, London.
1862 George was born in Scotland, one of ten children; brother of Thomas Octavius Callender[1]
1901 Civil engineer[2]
1903 Presumably had established his own business George M. Callender and Co