Theosophy and Ceylon
Hack became associated with Theosophy and some time before 1894 began adding the initials "F.T.S." to his name. He wrote a hymn "Abide with Me" in 1899, to be found in Theosophical literature, (based on the famous hymn by Henry F Lyte) as well as several books influenced by Theosophical thought. This interest in Eastern philosophy coincided with an involvement in two educational establishments in Ceylon (now Sri Lanka):
On returning from England to Australia around 1892, Hack visited the Buddhist girls' school run by Mrs Marie Musaeus Higgins in Colombo (its first principal was a Victorian, Kate F. Pickett, who died shortly after taking up the position), and was sufficiently impressed to promise funds for a more suitable schoolhouse than the mud hut they were using. This was forthcoming and the Musaeus College's first permanent school building was completed in 1895. He remained a member of the board of trustees until his death.
In 1899 he succeeded Harry Bambury as president of Buddhist boys school Dharmaraja College in Kandy, and did much good work in raising funds, but ill-health interfered and he retired after only a few months, to be succeeded by C. S. Rajaratnam then K. F. Billimoria.
Back in Australia
He returned to Glenelg early in 1900 and became active in the local community, as organiser of a Benevolent Society, vice-president of the United Labor Party, and served as a magistrate.
In mid-1915 he moved to Western Australia, where his sons William and Charles were working. He married again and never returned to South Australia.
He married Anna Maria Stonehouse (d. 13 August 1911) on 10 May 1870
- only daughter Florence Maria Hack (11 November 1871 –) m. William Norman Grant Mackenzie on 6 April 1904
- eldest son William Wilton Meora Stephen Hack (d. 12 February 1941) m. Charlotte Scott Murray on 25 September 1902
- second son Charles Corey Hack m. Ethel G. H. A. Maconochie on 29 October 1926
- youngest son Wilton (1 September 1878 – 10 April 1933) m. Amelia Ellen Cock on 30 April 1903
He married Minnie Alice Vierk of Farrell Flat, South Australia on 26 April 1916