Missing Persons
In the 19th century people advertised in Lloyd's Newspaper (and possibly elsewhere) for relatives with whom they had lost touch. The following are all available through the free newspaper site for Australia (Trove) at https://trove.nla.gov.au/newspaper.
1892 William Langdon sailed for Australia aboard the Ophelia. He wrote from Sydney in 1886, when he had been thinking of going to San Francisco.
Australian Town and Country Journal (Sydney, NSW) 16 April 1892 p33 col4
William wrote to Lloyd's in September. He was still in Sydney
Australian Town and Country Journal (Sydney, NSW) 3 September 1892 p29 col4
1896 The mother of George Morrish was seeking news of her son. He went to Queensland in 1886.
Australian Town and Country Journal (Sydney, NSW) 1 February 1896 p47 col1