William Harper Twelvetrees
Twelvetrees was born in Bedfordshire, England, in 1848, and educated in London and in Germany. From 1871 to 1880 he was employed at copper mines in eastern Russia, and from 1882 to 1890 at the Lidjessi silver-lead mines in Asia Minor of which he was general manager from 1884.
He went to Tasmania in 1890 and followed various occupations until August 1899, when he was appointed Tasmanian government geologist and chief inspector of mines.
In 1914 the office of chief inspector of mines was made a separate one, but Twelvetrees continued to act as government geologist and director of the geological survey of Tasmania until his death. He worked with energy and enthusiasm and his department grew in size and importance. He also interested himself in the Launceston Museum, which was extended so that the excellent geological survey collection of specimens could be housed. He died at Launceston after a short illness on 7 November 1919 
His writing in the bulletins of the Tasmanian geological survey and other publications, occurred at a very busy time in the West Coast, Tasmania region's mining history, which has not been repeated since.
Example of reports
- Twelvetrees, W.H. (1903), The Progress of the Mineral Industry of Tasmania for the Quarter Ending 31 December 1902.
- Twelvetrees, W.H. (1905), The Progress of the Mineral Industry of Tasmania for the Quarter Ending 31 December 1904.
- "GOVERNMENT GEOLOGIST.". Launceston Examiner. LIX, (186). Tasmania, Australia. 5 August 1899. p. 7. Retrieved 19 November 2016 – via National Library of Australia.
- Twelvetrees, William Harper; Petterd, William Frederick (1898), Supplementary note on Limurite in Tasmania, retrieved 18 November 2016
- Twelvetrees, W. H. (William Harper); Petterd, W. F. (William Frederick) (1898), [Collection of articles on geology, petrology and palaeontology in Tasmania], s.n, retrieved 18 November 2016
- "Death of Mr. W. H. Twelvetrees". Zeehan and Dundas Herald. XXXI, (23). Tasmania, Australia. 8 November 1919. p. 2. Retrieved 19 November 2016 – via National Library of Australia.
- Twelvetrees, W. H. (William Harper) (1900), Reports on the mineral districts of Mounts Huxley, Jukes and Darwin, Government Geologist's Office, retrieved 19 November 2016
- Twelvetrees, W. H. (William Harper) (1901), Report on the Mount Farrell district, John Vail, Govt. Printer, retrieved 19 November 2016
- Twelvetrees, W. H. (William Harper) (1900), Report on the mineral districts of Zeehan and neighbourhood, J. Vail, Govt. Printer, retrieved 19 November 2016
- Twelvetrees, W. H. (William Harper); Tasmania. Government Geologist's Office (1906), Report on the Renison Bell tin-field, Government Geologist's Office, retrieved 19 November 2016
- Serle, Percival (1949). "Twelvetrees, William Harper". Dictionary of Australian Biography. Sydney: Angus and Robertson.
- Blainey, Geoffrey (2000). The Peaks of Lyell (6th ed.). Hobart: St. David's Park Publishing. ISBN 0-7246-2265-9.
Arthur Smith Woodward