South Australia loses a strip of land to Victoria from mistaken 19th Century survey of the 141st meridian border

An illustration by S.T. Gill of the basic conditions for 19th Century Australian colonial border surveys. The map shows the zigzag border anomaly that saw South Australia lose a strip of its land to Victoria in a mistaken survey of the 141st meridian.
The state border between South Australia and Victoria remained an anomaly in the 21st Century, with the 1,420 square kilometres lost by South Australia occupied by some people who identified more with it than Victoria. The anomaly was due to compounded 19th Century survey errors.
The 1836 letters patent for South Australia corner declared its eastern border with then only New South Wales was the 141st meridian. From 1839, South Australia and New South Wales surveyors found it difficult, with then technology, to mark out a boundary according to the meridian.
To fix this, South Australian governor George Grey suggested the border be the Glenelg River (east-west through later Victoria and turning south to the Southern Ocean). New South Wales suggested using the River Murray – right through to its mouth, taking much of South Australia. Unable to agree on these alternatives, they reverted to the 141st meridian boundary.
In 1839, New South Wales south of the River Murray became the District of Port Phillip and, from 1851, the colony of Victoria. The new Victoria inherited its western border from New South Wales. A land survey was needed to confirm the 141st meridian. In 1839, surveyor Charles Tyers left a giant arrow of limestone rock east of the Glenelg River mouth, at what he calculated as the 141st meridian and starting point for an inland survey. Owen Stanley, captain of HMS Britomart, disputed Tyer’s mark as 2.25 miles east of the 141st meridian. But Stanley’s correction was due to faulty equipment. Tyers had been right.
By the 1840s, land disputes between sheep farmers in the area between the Murray and the sea demanded the border between South Australia and the District of Port Phillip be demarcated. In 1847, surveyor Henry Wade laid down 123 miles of border in a south-north line – starting from the point set by Stanley instead of Tyers. Due to harsh conditions, Wade gave up surveying about 155 miles south of the Murray River. But both South Australia and New South Wales soon accepted his line as the boundary between them.
In 1849, Wade’s fellow surveyor Edward White completed marking the boundary north to the Murray but in even harsher conditions. After two weeks in the Big Desert, his men had mutinied and when his last horse was dying, White drank half a pint of its blood – “thick, black and unhealthy-looking,” he wrote in his diary. White staggered on for two more miles, reaching the Murray and completing the survey.
By that time, it was already clear the Wade-White line wasn’t the true meridian. Both sides having accepted the line for what it was, the new state of Victoria in 1851 inherited the mistake in its favour.
In 1868, it was time to demarcate the South Australia-New South Wales border north of the Murray. With better survey instruments, South Australia and New South Wales agreed to revert to the original 141st meridian. As a result, South Australia’s eastern border followed the Wade-White line south of the Murray and the 141st meridian to the river’s north. Hence the zigzag at the tripoint with New South Wales and Victoria, called MacCabe Corner. For South Australia, that zigzag was a reminder of what it had lost: a strip between the River Murray and the sea, 2.25 miles wide and 280 miles long.
For decades, South Australia disputed Victoria’s ownership and tried reclaiming the strip or get compensation. But by 1849, the District of Port Phillip had sold or leased out 47% of the disputed land. The contested strip of land became a legal grey zone. In the 1901 federation referendum, one local cast his vote as a Victorian one day and a South Australian the next.
The states took their border battle to the Australian high court that ruled in favour of Victoria, confirming the border at 141 degrees but it couldn't be changed despite technology advances. In 1914, an appeal to the privy council in London favoured Victoria. The council acknowledged the survey mistake but that the border had been accepted by both sides.