In a memorandum of 28 September 1860 he wrote "the western boundary ... appears to be the 141st meridian; but it is probable that it was not described in the Letters Patent erecting the Colony, with greater distinctness, expressly with a view to a future adjustment, when more certain information should have been collected as to the natural features of the country...

It is now submitted that the 141st meridian passes through the tract of country known as the "Plains of Promise" and that the Eastern shore [of the Gulf of Carpentaria] possesses no harbours.

It would therefore be desirable to adopt the 138th meridian as the boundary; as that line would pass through a barren tract of country, and bring "Investigator's Road' [an anchorage] within the limits of Queensland.

'[1][4] Furthermore, expeditions in 1861-1862 funded by the South Australian, Victorian and Queensland governments to rescue the missing explorers Burke and Wills, who had failed to return from a journey from Cooper Creek to the Gulf of Carpentaria, led to the exploration of an enormous area of the inland and were predicted to stimulate interest in this previously unknown tract of land beyond Queensland's western boundary.

[1][5] In response, a despatch dated 14 December 1861 from the Secretary of State for the Colonies advised that the proposed annexation to the 138th Meridian of longitude should be revoked under Act 24 and 25 Victoria, c.44.

This immediately provoked a despatch from Sir George Bowen, dated 18 January 1862, stating that Queensland had taken provisional control of this area.

[6] Thereby two more corners in Queensland's western boundary were created and the colony acquired part of the Barkly Tableland and the area which later became the Mount Isa mineral field.

[1][8] In July 1862 Sir Charles Nicholson[9] reported to the Secretary of State for the Colonies that: "On the west, the whole of the basin of the 'Barcoo' for several hundred miles, as far as the 142nd meridian of East longitude, is becoming rapidly occupied by squatters, and the authorised possession of the greater part of it has already, I believe, been secured under pastoral licenses".

This land, comprising the floodplains of the Mulligan, Georgina, Diamantina and Bulloo Rivers and Cooper Creek, which form part of a vast inland drainage system originating in Queensland's central west and north-west and eventually reaching Lake Eyre, became known as Channel Country.

In 1877 James McLeod, the new owner of Cullamurra run, applied to the South Australian Commissioner of Crown Lands to have the colony's border surveyed urgently, after finding himself in dispute with his eastern neighbour John Conrick of Nappa Merrie over their station boundaries.

A small Customs Border Patrol consisting of a police inspector, sub-inspector and four constables was appointed with powers to collect duties from 1 January 1871.

[17] The surveyor chosen to undertake the border survey was William Barron, who had recently accompanied an expedition to South Australia's western districts.

In May 1879 Barron, accompanied by a survey team with horses and camels, set out from Mulligan Springs, 24 kilometres (15 mi) east of Mount Hopeless in north-east South Australia.

The work was difficult and tedious, involving trudging over sand ridges and claypans, and marking the line by mileposts recording the distance from the survey starting point at the Murray River.

[5] William Barron marked the border from Cameron Corner 90 miles (140 km) north to Cooper Creek, where his health failed and he was forced to return to Adelaide.

Arriving at the survey camp at Innamincka on 3 February 1880, Poeppel spent the following month taking observations and preparing rations and equipment.

The corner was marked with a willow post, 12 feet (3.7 m) long, sunk over an iron bar flanked by rock trenches following the angle.

In 1878, after short periods in New Zealand and Western Australia, Poeppel joined the South Australian Lands Department and was soon appointed to the border surveys.

During the Queensland-Northern Territory border survey, from the 142-mile post, he suffered from trachoma and lost 13 kilograms (29 lb) in weight, forcing his withdrawal in July 1885.

Set borders were an important part of colonial economic and administrative development, providing certainty for governments and pastoralists, and enabling the collection of customs duties.

[1] Haddon Corner is the result of early cooperation between Australian colonies and provides lasting evidence of the feat of endurance which marking the Queensland-South Australia border involved.