There are dog-legs, curves and even boundaries that do not line up in the borders of South Australia.

South Australia’s surveyor-general Michael Burdett said although a little wonky by today’s standards, the accuracy of the borders was pretty impressive given the tools used to create them.

“Back in the mid-1800s, the technology was a long way from where we are today,” he said. “They were using sextants, circumferentors and low-level theodolites to try and do their work.”

And the conditions the surveyors had to work in were brutal. This is how each border came to be.

The south-eastern border

The eastern border is much noted for the 70-odd year battle over the border south of the River Murray.

It was meant to run along the 141st meridian line of longitude.

But longitude is measured with time references to Greenwich Mean Time – and watches were not that great in the 1800s.

The result was a 3.6-kilometre gap where the borders were meant to have met.

William Hatton (R) and a surveyors on site in 1912. Photo: State Library of South Australia

“Fundamentally the difference came down to a discrepancy that the nation had at the time,” Mr Burdett said.

“The longitude that had been determined for Fort Macquarie [Australia’s reference point] was out by two minutes.

“Hence ours was out by two minutes and the discrepancy ended up in that border.”

The 1295 square kilometre allotment became the focus of a legal dispute from 1849 to 1911, when the High Court ruled the surveyor’s pegs were the legal line.

The north-eastern border

Although the disputed territory of the south-eastern border took most of the attention, the northern edge was not exactly accurate either.

A bushfire passed through the area of the SA/NSW border a year after it was marked, destroying many of the survey markers.

When fences were laid to mark the border, teams erred of the side of caution and the line moved 200-600 metres inside the NSW side.

“South Australia managed to grab back a bit, and that is a piece [of land] that we still have unresolved today,” Mr Burdett said.

Surveyor George Dodwell used this theodolite to measure some of SA’s borders. Photo: ABC

Poeppel Corner

On the edge of the NT/Queensland/SA border, Augustus Poeppel marked what is now known as his corner in 1880.

“When they returned to Adelaide with their equipment, they standardised their [measuring] chain and found it was too long,” Mr Burdett said.

As a result, the corner had been placed 200 metres too far to the west.

But when Mr Poeppel returned the following year to mark the NT/Queensland border, he shifted the marking post to the correct spot.

The northern edge

Although straight on a flat map, the northern edge is actually periodically angled to take into account the curvature of the Earth.

“You actually have to lay it out as chords of an arc,” Mr Burdett said.

The chords are in 32km lengths, with slight adjustments made at each end.

The north-western corner

The Western Australian border was initially mapped in the 1920s.

A longitude of 129E was agreed on for the separation line. A beacon was placed on the SA/WA border at Deakin in 1926.

CM Hambidge with the Deakin Obelisk on SA/WA border in 1926. Photo: State Library of South Australia

A second was placed on a cattle station in the Kimberley to mark the WA/NT border.

A decision was then reached that the border would exist between the northern and southern lines of those markers.

When they met at the NT/SA border in 1968, the borders were found to be 127.4 metres out.

Markers were placed on both edges, and they remain that way to this day.

Surveying was a life and death occupation

Although in today’s terms the errors and variances are comical, Mr Burdett said the work for its time was incredible.

“I have great respect for the work that was done in the early days,” he said.

“We go out [now] and concentrate on doing a survey; these people went out and had to concentrate on staying alive.

“[Surveyor Edward R] White surveyed for 250 kilometres, in conditions that almost killed him and his team, and was within 30 metres due north of his starting point.

“Fair credit to the man and the fact that none of them died.”

-ABC