Eyre’s ‘horseshoe lake’ would bar northern progress for another 17 years, frustrating the attempts of the young colony to expand its horizons much beyond the head of Spencer Gulf. The horseshoe myth was challenged in the late 1850s when Acting Deputy Surveyor-General George Goyder reached Lake Torrens and found it surrounded by vegetation. In 1858 Babbage, Warburton and Gregory proved that the ‘horseshoe Lake Torrens’ in fact comprised many separate lakes. This is Frome’s map of his 1843 expedition.
As Surveyor-General, Frome attempted to find the southern boundary of the eastern section of the ‘horseshoe Lake Torrens’. He was unable to find this boundary on his expedition to the eastern side of the Flinders. This expedition went via Mt Bryan, Black Rock and Orrorroo, then east crossing the River Siccus, through Chambers Gorge, rode east to the flood plain of Chambers Creek, turned northwards and Wearing Gorge before turning west to re-enter the Flinders Ranges at Prism Hill near Moro Gorge on the Balcanoona-Junta Rd making it to Mt McKinley.
Frome’s watercolour of Prism Hill:
Frome had intended to doubling back with the intention of passing eastward around the southern end of Lake Frome. However provisions were short, water was hard to find, one of the party became separated from the main group and precious time was taken up with the search. The expedition turned back. Frome had established the southern and eastern limits of the mythical horseshoe lake they knew as Lake Torrens.
Eyre and Sturt were right in their belief that in earlier periods of geological time an enormous mega lake covered the present arid region of salt lakes (Torrens, Gregory, Callabonna, Blanche and Frome) surrounding the northern Flinders Ranges. That was when the rainfall in this region was much higher than the present, which is less than 250mm per annum. The Lake Frome mega lake dried out during the overlapping period when humans arrived and the Pleistocene megfauna (eg., the giant bird Genyornis newtoni and the giant marsupial Diprotodon) went extinct — 60,000–48,000 years ago.
At the end of the last ice age, Australia’s climate changed from cold-dry to warm-dry. As a result, surface water became scarce. Most inland lakes became completely dry or dry in the warmer seasons. The water levels in the Lake Frome mega lake (and Lake Eyre) fell between 50,000-40,000 years ago, after which these lakes filled only intermittently. The mega lake dried out because the rivers stopped flowing leaving the current arc of salt lakes.
Frome’s party reached Lake Frome in August 1843. They knew the lake as Lake Torrens as they still thought there was a mega salt lake semi circled around the northern Flinders from the western side of the Flinders (ie., Lake Torrens) which extended around to the easteren side of the Flinders (ie., Lake Frome). So they thought they were looking at the eastern edge of Lake Torrens. The early explorers (Eyre, Frome, Sturt, Stuart etc ) saw this arc as a salt barrier preventing them from going further north. This is the Horseshoe theory, and it was only seen to be a myth in 1858 when the Gregory Bros, searching for the lost explorer Leiichhardt, passed between Lake Blanche and Lake Callabonna from outside the horseshoe and reached Mt Hopeless.
A diary was kept by Hawker, a pastoralist who was part of Frome’s party. He had joined them when Frome’s party arrived at his sheep station ‘ Bungaree’ on their way to the lake. This is Hawker’s description of Lake Frome:
“We rode across a barren plain with nothing on it but a few stunted salt bushes and in about 2 hours and a half we came to the shores of the far-famed Lake Torrens. It was by far the most dreary and desolate sight I ever saw.The lake, if it can be called such, was an extensive plain of sand covered with salt with no water in it for as far as we could see, although it had evidently been flooded not long before. All along its banks were low hillocks of drifted sand but no vegetation except a few saltbushes. The salt on the sand was what appeared to us like water at a distance. After remaining a short time turned back towards the hills keeping westerly course.”
The ‘we’ in the party were Frome, Henderson who made a number of pencil sketches on the expedition, and Hawker. Their provisions were running low by this stage of the expedition and they were on rations. James Henderson was a member of Frome’s Expedition to Lake Frome and he kept a journal and a sketchbook of 42 drawings. This extract is from Henderson’s diary:
“Frome, Hawker and I rode down eastward see the lake. We expected to have only a short ride of about eight or nine miles, but we had ridden a good 15 before we came to the shores of this wonderful lake, from the bed of which dust rose in clouds! As for water, not a drop could be seen. All the beautiful islands that we had seen from the hills were in reality merely small hillocks in the immense plains of white sand, and the mirage caused the reflection of these island when we first saw them from the ranges. There was no doubt in our minds of water at some time having covered, although at a depth of only a few inches, the immense sand sea, but the thick coating of salt in many places proved at once the quality of the water where is any. All our dreams of discovering a large lake of fresh water now vanished, and we turned with disgust on this dreary spot and made the best of our way back.”
From what I can gather neither Frome nor Henderson made any water colours or pencil sketches of Lake Frome itself. Henderson only made a few watercolours from his pencil sketches.
Frome’s water colours are part of the collection at the South Australian Art Gallery. (https://www.agsa.sa.gov.au/collection-publications/collection/creators/e-c-frome/3235/). James Henderson’s pencil sketches and his water colours are in a collection at the State Library of South Australia (https://collections.slsa.sa.gov.au/resource/B+2434/1-43). There is a book of Frome’s expedition to Lake Frome entitled Journey to Lake Frome 1843 : paintings and sketches by Edward Charles Frome and James Henderson by Ian Auhl and Denis Marfleet.