Foot­loose RON MOON

4 x 4 Australia - - Contents - RON MOON

IWAS cruis­ing down the Stu­art High­way a few days ago when I stopped at the rest area at Cen­tral Mount Stu­art, about 260km north of Al­ice Springs. The cairn erected here back in 1960 stands close to the high­way, while the peak is just a few kilo­me­tres west and plainly vis­i­ble from the road.

John Mc­douall Stu­art, pos­si­bly Aus­tralia’s great­est ex­plorer, named the peak in April 1860 when he found – by ob­serv­ing the sun – that he was camped in the cen­tre of Aus­tralia. Like any good ex­plorer he marked a tree and planted the Bri­tish flag.

Charles Sturt had ear­lier planned to be the first Euro­pean to reach the very heart of the con­ti­nent. Before he set off on his mon­u­men­tal 1844 ex­pe­di­tion, he said: “Let any man lay the map of Aus­tralia before him, [what an] hon­ourable achieve­ment to be the first to place foot at its cen­tre.”

Stu­art was on that ex­pe­di­tion with Sturt, and when he found him­self in the heart of Aus­tralia 16 years later he named the peak Cen­tral Mount Sturt in recog­ni­tion of Sturt and his con­sid­er­able achieve­ments.

Only later was the peak’s name changed, and for more than 100 years that peak was con­sid­ered the cen­tre of Aus­tralia. Now there are a few more.

In 1965, as part of a ma­jor up­grade to sur­vey­ing, the Aus­tralian Geode­tic Da­tum (AGD) was es­tab­lished as the stan­dard map­ping sys­tem in the coun­try (since re­placed by the even more ac­cu­rate Geo­cen­tric Da­tum of Aus­tralia) and the John­ston Geode­tic Sta­tion in cen­tral Aus­tralia was a ma­jor ref­er­ence point.

This cairn was built by the Di­vi­sion of Na­tional Map­ping and is lo­cated about 1km north of Mount Cave­nagh home­stead – just north of the SA/NT bor­der.

Then in 1988 the Royal Ge­o­graph­i­cal So­ci­ety of Aus­trala­sia, look­ing for some­thing to cel­e­brate the bi­cen­ten­nial, de­cided to work out the grav­i­ta­tional cen­tre of Aus­tralia. The lo­ca­tion, now called the Lam­bert Grav­i­ta­tional Cen­tre, was cal­cu­lated from 24,500 points spread around the high-water mark of Aus­tralia’s coast­line, and a ma­jor mon­u­ment has been erected 32km north of the Kul­ger­afinke road.

Re­searchers at Geo­science Aus­tralia have now come up with a few more ‘cen­tres of Aus­tralia’. The ‘fur­thest point from the coast­line’ was found by – rather crudely, I thought – draw­ing a se­ries of con­cen­tric cir­cles on a piece of trans­par­ent ma­te­rial and mov­ing that over the top of a 1:5 mil­lion scale map of Aus­tralia.

The cen­tre point in this case was at the cen­tre of the largest cir­cle that could be drawn in­side Aus­tralia while still just touch­ing the coast­lines. This point is lo­cated north-west of Al­ice at 23°02’0” south, 132°10’00” east.

GA’S ‘cen­tre of grav­ity point’ was worked out from more than 50,000 digi­tised points around the Aus­tralian coast, and each was as­signed a weight. The re­sul­tant cen­tre point is where you could, the­o­ret­i­cally, bal­ance Aus­tralia on a pin. It’s lo­cated – to the sur­prise of all con­cerned, ap­par­ently – very close to the ‘fur­thest point from the coast­line’ marker, at 23°07’00” south, 132°08’00” east.

This wasn’t the first time some­one had tried to find Aus­tralia’s cen­tre of grav­ity. In the 1930s, when Dr CT Madi­gan trav­elled through Cen­tral Aus­tralia and across the north­ern Simp­son Desert, he cal­cu­lated the cen­tre of grav­ity by us­ing a me­tal cut-out of Aus­tralia with a plumb bob and string. His mea­sure­ment was sur­pris­ingly ac­cu­rate, as he se­lected a point less than 11km due west of the Lam­bert Grav­i­ta­tional Cen­tre and not all that far from the cen­tre of grav­ity point se­lected by Geo­science Aus­tralia.

The me­dian cen­tre point of Aus­tralia was cal­cu­lated as the mid­point be­tween the ex­tremes of Aus­tralia’s lat­i­tude and lon­gi­tude. That point is lo­cated at 24°15’00” south, 133°25’00” east, and is not far west of the Stu­art High­way, south of Al­ice Springs.

You can find more info at: www.ga.gov.au (search for ‘cen­tre of Aus­tralia’). For me, I’ll stop at the Cen­tral Mount Stu­art me­mo­rial when­ever I go past, and one day in the not-too-dis­tant fu­ture the John­ston cairn may tempt me to leave the high­way.

The cairn at Cen­tral Mount Stu­art (above); the Lam­bert Grav­i­ta­tional Cen­tre (be­low). More Foot­loose at: www.guide­books.com.au/foot­loose.htm

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