Lindsay became an apprentice in the state government survey department in 1873. In 1878 he was appointed ("gazetted" in Public Service parlance) as a senior surveyor in March 1875. In 1878 he was appointed junior surveyor and clerk in the land office of the Department of the Northern Territory at Palmerston (now Darwin) in the Northern Territory. In 1882 he resigned from the government service to take up private practice, but about a year later was placed in charge of a South Australian government expedition to Arnhem Land (in the Northern Territory). The party, consisting of four white men and two Indigenous Australians, met with a hostile response from local Aboriginal people, and drove them off with firearms. Some of the horses had been stampeded during the conflict and the explorers only reached civilisation after suffering many privations. Lindsay subsequently explored territory between the Overland Telegraph Line and the Queensland border and discovered Australia's first payable mica field. In 1886 Lindsay was exploring in the region of the MacDonnell Ranges and discovered so-called rubies. The 1885–86 expedition traced the Finke River to its mouth.