James Harthen was born in Broughton, near Manchester, England in 1860 or 1861. He was educated in England and came to Tasmania in his early 20s. He married Jane Fotheringham King and had eight children: John James Henry, born 1891; James Henry, 1893; Agnes May, 1896; twins Christina Grace and Annie Louisa, 1898; Helen May, 1901; Mabel, 1909 and Walter Charles, 1911.
He was a student at the Launceston Technical School at the time of the Tasmanian Exhibition in 1891-92 and submitted drawings to scale of launch engines from fully dimensioned sketches. His occupation is listed as engineer in the 1903 Electoral Roll.
James was employed in the workshops of the Tasmanian Government Railways from 1909 until his retirement in 1931 when he was an engine fitter. He was a prominent member of the Amalgamated Engineers' Union, serving as president and in other offices over many years, and was a member of the Heart of Oak and Austral Light Lodge and Ancient Order of Druids.
He died in Launceston on 14 Jun 1938 aged 77 and was buried at Carr Villa with his wife Jane who had died on 13 Dec 1931. They are buried in Section B1 No. 223.