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). 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. of the Sydney Museum and Streich, a German geologist and mineralogist. Starting from Warrina, South Australia, with 42 camels The scope of the Elder Scientific Expedition, funded by Sir Thomas Elder, included recording fauna, flora, geological structures and climate, mapping the territory, potential for pastoral development, recording original indigenous place names, languages and pronunciation, avoiding conflict with indigenous tribes and to investigate the disappearance of
Ludwig Leichhardt. The expedition occurred during a period of extensive drought. Aided by indigenous people, water was not only sourced but evidence of water harvesting and management of evaporation through shoring up water sources with rocks and branches was observed. Lindsay records a 'solitary mia-mia (temporary shelter) formed of bamboo thickly thatched with grass , 6 ft high 10 ft in diameter ..with one entrance…so small I had the greatest difficulty in squeezing through it…the natives told me that when occupied , the entrance was stopped up with grass to keep out mosquitoes. It was used at the beginning of the wet season (to gather) wild fowls eggs and a stopping place from one route to another during the wet season'Lindsay notes the use of fishing: 'saw a native fishtrap made of “ supple jack" woven like a basket, 18 ft long and gradually tapering from 3 ft wide at its mouth, leaving at one side a hole to which the mouth of the reap is fixed. As the ride goes in or out the fish coming with it find a barrier, then with a rush, they go through what they suppose to be an opening, but which is in reality a trap, with a blackfellow at the other end ready to pop them into his basket as they come through the hole'. In general, however, the expedition in Arnhem Land was fraught with hostility between indigenous people and white people. It appears that Lindsay was reluctant at first to engage in hostilities which he encountered especially around Castlereagh Bay, the Roper River and in the locality of the Wornunyan Woorie. 'Were I to go there again I would shoot the first blackfellow I saw'. ==Later life==