the border. A bottle containing concrete and an empty brass cartridge case was sunk 2½ feet below every fifth wooden post. Bedford's second in command, William Davidson, in later years wrote:"As white ants were very bad out there, it is quite possible that very few traces remain of our work above ground, but perhaps the bottles of cement we placed at every five miles along our line may prove interesting to scientists of some future generation, should they ever be unearthed."In 1988, as a special project for the Australian Bicentenary, the Queensland Division of the Institute of Engineering and Mining Surveyors of Australia retraced Bedford's survey and found his bottles. Fixing the longitude In 1887, Queensland staff surveyors Robert Hoggan and Robert Grant McDowall carried out observations at the post and telegraph station in Boulia. This fixed the longitude of Bedford's initial starting point. The method used was the exchange of time signals via the electric telegraph. This was between the Brisbane Observatory of known longitude, and Bedford's starting point beside the telegraph office in Boulia. By using a traverse they were able to obtain a longitude value for the mile post out on the border west of Boulia. Bedford's observation revealed that the mile posts placed on the border by the South Australian surveyors were accurate. See also Queensland and New South Wales boundary encroachments References Attribution This article was based on material from History of Queensland borders before proclamation, Queensland's borders since proclamation, Surveying the Queensland New South Wales border, Surveying the Queensland South Australia border and Surveying the Queensland Northern Territory border published by The State of Queensland 2018 under CC-BY-4.0 license, accessed on 7 October 2018. Further reading Borders of Queensland Articles incorporating text from the Queensland Government Borders of New South Wales Borders of South Australia Borders of the Northern Territory