This file is in the public domain because the image was created before 1 January 1955. The Australian Government's authoritative guide to the Copyright Act 1968 (Short Guide to Copyright, November 2016 – https://www.communications.gov.au/documents/short-guide-copyright) states (on page 11) that "The term of copyright protection for photographs taken before 1955, regardless of whether the author has since died or is still alive, has expired".