Alanson was a highly respected teacher in NSW country areas in the 1880s and 1890s. In 1900 he was moved to Sydney, and from 1907 until his retirement in 1929 he taught at Randwick Public School, which was generally know as "Alanson's school", such was the beneficial effect he had on it. He was President of the NSW Public Schools Teachers' Association 1909-10 and of the Australian Teachers' Federation 1923-24. From 1908-14 he wrote a weekly column on education for the Sydney Morning Herald and then edited the journal Education from 1919 to 1939. He published a grammar textbook (as A. G. Chapman) and wrote several children's books, the most notable being Terraweena, published in 1905 under the pseudonym Russell Allanson, and now much sought after by collectors. He also wrote Kurnell : the Birthplace of Australia (1933). Alanson was a strong supporter of Australian literature and played an important role in the commissioning of the Henry Lawson statue in Sydney.
