Journals of Australian Explorations Part 52

Lat.i.tude 26 degrees 2 minutes.

1st June.

The channels on the western side of the plain were very irregular, sometimes completely lost on the level surface, and again collecting into large hollows, with box-trees on the banks, in which fine sheets of water still remained, some 100 yards wide and more than a mile in length. We therefore did not experience so much inconvenience with regard to the supply of this necessary element as from the absence of sufficient gra.s.s, and the all but impracticable nature of the mud plains.

4th June.

In lat.i.tude 27 degrees, low sandstone tableland approached the west side of the river, and we attempted to travel along the slope between it and the mud plains, but found it so stony that the horses' hoofs were soon worn to the quick, as we had been compelled to remove their shoes to enable them to traverse the mud plains. Had it not been for green bushes of salsolae, and some similar plants which had sprung up since the rain, this tract of country exactly resembled the stony desert described by Captain Sturt as existing 200 miles to the westward. These remarkable features forming the declivities of the sandstone tableland through which Cooper's Creek forces its way, and by confining the waters to a narrower s.p.a.ce during floods, causes the fine deep reaches of water which characterize it.

8th June.

By following the western limits of the plains we reached lat.i.tude 27 degrees 30 minutes, when the sandstone tableland receded, and a boundless expanse of mud plain was before us; the lines of box-trees which had hitherto marked the channels nearly ceased, polygonum and atriplex const.i.tuting the main feature of the vegetation.

COOPER'S CREEK.

9th June.

After toiling south-west a day and a half over this level surface to lat.i.tude 27 degrees 50 minutes, we approached some low ridges, at the foot of which there was a lagoon 100 yards wide, exhibiting signs of a current during flood to the north-west; and as there was an evident westerly trend in all the smaller channels previously crossed, it was evident they would soon merge in Cooper's Creek. Steering west-north-west, the several channels collected together, and soon formed a deep watercourse, with fine reaches of water. The sandstone tableland closed in on both sides; the soil of the intervening plain was much firmer, but showed by the vegetation that saline nature which so often attends the development of the upper sandstones in Australia. Gra.s.s was abundant, and it was surprising with what rapidity the horses recovered their strength.

BOUNDARY OF SOUTH AUSTRALIA.

12th June.

Approaching the 141st meridian, which is the boundary of the province of South Australia, stony ridges closed in on both banks of Cooper's Creek, forming almost a natural division, across which we followed a well-beaten native path; and here I observed the only instance which has come under my observation where the aborigines have taken the trouble to remove natural obstacles from their paths. The loose stones had been cleared from the track, and in some places piled in large heaps.

14th June.

After pa.s.sing the stony ridge the valley became wider, the hills receding suddenly, in longitude 140 degrees 30 minutes, both to the north and south; and the whole of the country to the west seemed to consist of a succession of low ridges of red sand and level plains of dry mud, subject to inundation. Shortly before reaching the branch of Cooper's Creek named by Captain Sturt Streletzki Creek, we observed the tracks of two horses, one apparently a cart-horse, and the other a well-bred animal, but as none of their tracks were within the last month, the rain had obliterated them to such an extent that they could not be traced up, as they had left the bank of the creek on the first fall of rain, as is the usual habit of horses whose wanderings are uncontrolled. There can be little doubt that these horses belonged to Captain Sturt, who left one in an exhausted state near this locality, and also lost a second horse, whose tracks were followed many miles in the direction of this part of Cooper's Creek.

16th June.

Streletzki Creek, which separates nearly at a right angle from the main channel, appears to convey about one-third of the waters of Cooper's Creek nearly south, and, as we afterwards ascertained, connects it with Lake Torrens. We, however, continued to follow the channels which trended west for thirty miles, but large branches continually broke off to the south and west, and at length the whole was lost on the wide plains of dry mud between the sand ridges; and, as there was no prospect of either water or gra.s.s to the west, I steered south and south-east for fifty miles over a succession of ridges of red drift sand, ten to fifty feet high, running parallel to each other, and in a nearly north and south direction. Between these ridges we occasionally found shallow puddles of rainwater, or rather mud, as it was so thick with clay as to be scarcely fluid. Fortunately a great quant.i.ty of green weeds had grown up since the rain, and the horses improved in condition, and did not require much water.

21st June to 25th June.

In lat.i.tude 28 degrees 24 minutes we again came on Streletzki Creek, and then followed it nearly south-south-west between sandy ridges to lat.i.tude 29 degrees 25 minutes, when it turned to the west and entered Lake Torrens. No permanent water was seen in the bed of the creek, though there were many deep hollows which, when once filled, retain water for several months, and this, combined with the existence of a fine reach of water in Cooper's Creek immediately above the point where Streletzki Creek branches off, renders it far the best line of route into the interior which has yet been discovered. Pa.s.sing between the eastern point of Lake Torrens and what has. .h.i.therto been considered the eastern arm, but now ascertained to be an independent lake, the s.p.a.ce between (about half a mile) was level sandy ground, covered with salicornia, without any apparent connecting channel. The course was continued south-south-west towards Mount Hopeless, at the northern extreme of the high ranges of South Australia, which had been visible across the level country at a distance of sixty miles.

26th June.

As we approached the range of hills tracks of cattle and horses were observed, and eight miles beyond Mount Hopeless came to a cattle station which had been lately established by Mr. Baker. As the nature of the country we had traversed was such as not to admit of any useful deviations from it if we returned to New South Wales by land, I deemed it advisable to proceed forthwith to Adelaide, and, disposing of the horses and equipment, return with the party by sea to Sydney.

ARRIVE IN ADELAIDE, SOUTH AUSTRALIA. GENERAL OBSERVATIONS.

31st July.

We therefore proceeded by easy stages towards Adelaide, experiencing the greatest hospitality at the stations on our route, while our reception in the city was of the most flattering nature. His Excellency Sir Richard Macdonald kindly gave me the use of an extensive paddock for the horses, and provided quarters for the men during the period which necessarily elapsed before the sale of the equipment of the expedition was effected.

I have also to express my acknowledgments of the kind a.s.sistance rendered by the Honourable the Commissioner of Crown Lands, to the Surveyor-General, and the Superintendent of Telegraphs, for valuable data connected with the construction of the map of the route, as well as to many other gentlemen whose cordial co-operation greatly facilitated my arrangements. It is extremely gratifying to record my appreciation of the untiring zeal and energy which distinguished every individual composing the expedition; and it is to the unvarying and cheerful alacrity with which each and all performed their respective duties, that, under Providence, the rapidity and success of the journey is to be mainly attributed. With reference to the probable fate of Dr. Leichhardt, it is evident, from the existence of the marked camp, nearly eighty miles beyond those seen by Mr. Hely, that the account given to that gentleman by the natives of the murder of the party was untrue; and I am inclined to think only a revival of the report current during Leichhardt's first journey to Port Essington. Nor is it probable that they were destroyed until they had left the Victoria, as, if killed by the natives, the scattered bones of the horses and cattle would have been observed during our search. I am therefore of opinion that they left the river at the junction of the Alice, and, favoured by thunder-showers, penetrated the level desert country to the north-west; in which case, on the cessation of the rain, the party would not only be deprived of a supply of water for the onward journey, but unable to retreat, as the shallow deposits of rainwater would evaporate in a few days, and it is not likely that they would commence a retrograde movement until the strength of the party had been severely taxed in the attempt to advance. The character of the country traversed, from the out-stations on the Dawson River to the head of the Warrego River, was generally that of a gra.s.sy forest, with ridges of dense brigalow scrub. A great portion is available for pastoral purposes, but not well watered; and the soil being sandy, the gra.s.s would soon be destroyed if too heavily stocked. As we advanced into the interior it became more barren, and, except along the banks of the larger watercourses, dest.i.tute of timber, and the character of the vegetation indicated excessive droughts. North of lat.i.tude 26 degrees dense scrubs of acacia prevailed on the level country beyond the influence of the inundations, but to the southward sandy and stony deserts, with low shrubby vegetation, were the characteristic feature. West of longitude 147 degrees, nearly to the boundary of South Australia, in 141 degrees, the country is unfit for occupation, for, though in favourable seasons there might in some few localities be abundance of feed for stock, the uncertainty of rain and frequent recurrence of drought renders it untenable, the gra.s.ses and herbage being princ.i.p.ally annuals, which not only die but are swept away by the hot summer winds, leaving the surface of the soil completely bare. On Cooper's Creek, near the boundary, there is a small tract of second-rate country, which, being abundantly supplied with water, may eventually be occupied. The best part is, however, within the province of South Australia. Between Cooper's Creek and Lake Torrens about 120 miles of sandy country intervenes. This tract is dest.i.tute of surface water, but as it is probable that it could be obtained by sinking wells of moderate depth, I think it might be occupied to advantage during the cool season, and thus relieve the stations which are now established within Lake Torrens, though I fear that the summer heat would be too great to admit of permanent occupation. The geological character of the country is remarkably uniform. Carboniferous sandstones and shales, containing occasional beds of coal, with superinc.u.mbent hills and ridges of basalt, extend from Darling Downs to the 146th meridian, where these rocks are covered by horizontal sandstones with beds of chert and water-worn quartz pebbles. This latter formation extends as far as Mount Hopeless, where the slate ranges of South Australia rise abruptly from the plain. The sandy deserts and mud plains are only superficial deposits, as the sandstones are often exposed where the upper formation is intersected by gullies. The direction of the parallel ridges of drift sand appear to be the result of the prevailing winds, and not the action of water, it being sufficient to visit them on a windy day to be convinced that it is unnecessary to seek for a more remote and obscure cause than that which is in present operation. It is, perhaps, with reference to the physical geography of Australia that the results of the Expedition are most important; as by connecting successively the explorations of Sir T. Mitch.e.l.l, Mr. Kennedy, Captain Sturt, and Mr.

Eyre, the waters of the tropical interior of the eastern portion of the Continent are proved to flow towards Spencer's Gulf, if not actually into it, the barometrical observations showing that Lake Torrens, the lowest part of the interior, is decidedly above the sea-level. Although only about one-third of the waters of Cooper's Creek flow into Lake Torrens by the channel of Streletzki Creek, there is strong evidence that the remaining channels, after spreading their waters on the vast plains which occupy the country between them and Sturt's Stony Desert, finally drain to the south, augmented probably by the waters of Eyre's Creek, the Stony Desert, and perhaps some other watercourses of a similar character coming from the westward. This peculiar structure of the interior renders it improbable that any considerable inland lakes should exist in connection with the known system of waters; for, as Lake Torrens is decidedly only an expanded continuation of Cooper's Creek, and therefore the culminating point of this vast system of drainage, if there was sufficient average fall of rain in the interior to balance the effects of evaporation from the surface of an extensive sheet of water, the Torrens Basin, instead of being occupied by salt marshes, in which the existence of anything beyond shallow lagoons of salt-water is yet problematical, would be maintained as a permanent lake. Therefore, if the waters flowing from so large a tract of country are insufficient to meet the evaporation from the surface of Lake Torrens, there is even less probability of the waters of the western interior forming an inland lake of any magnitude, even should there be so anomalous a feature as a depression of the surface in which it could be collected, especially as our knowledge of its limits indicate a much drier climate and less favourable conformation of surface than in the eastern division of the continent. The undulations of the surface of the country are nearly parallel to the meridian, gradually decreasing in height from the dividing range between the eastern and western waters till, instead of the waters of the rivers being confined to valleys, they occupy plains formed by a slight flattening of the curvature of the sphere. Thus the sides of the plain through which the river ran before it turned west to Cooper's Creek were 150 feet below the tangential level of the centre channels, and even the summit of the sandstone tableland which rose beyond was below the visible horizon. It is this peculiar conformation which causes the stream-beds to spread so widely when following the course of the valleys from north to south, and it is only where they break through the intervening ridges that the water is confined sufficiently to form well-defined channels. The existence of these extensive valleys trending north and south over so large a tract of country render it by no means unlikely that they continue far beyond the limits of present explorations, and it is not unreasonable to infer that the great depression which has been traced nearly five hundred miles north from Spencer's Gulf through Lake Torrens to the stony desert of Sturt (or rather the mud plains contiguous to its western limit) may be continuous for an equal distance beyond to the low land at the head of the Gulf of Carpentaria; a theory also supported by the fact that the rivers flowing into the Gulf either come from the east or west, apparently from higher land in those directions, while there is not a single watercourse from the south, or any indication of elevated country in that direction. Captain Wickham having named an important river discovered by him in H.M.S. Beagle, on the north-west coast, the Victoria, several years prior to Sir T. Mitch.e.l.l having attached that name to the upper portion of Cooper's Creek, which had also been previously discovered and named by Captain Sturt, I would suggest that the term River Cooper be adopted for the whole of the main channel from its sources, discovered by Sir T. Mitch.e.l.l, to its termination in Lake Torrens; as, while it does not interfere with the rule that the name given by the first discoverer should be retained, will prevent the recurrence of the misapprehension and inconvenience of having two important rivers with the same designation on the maps of Australia. With regard to the numbers and habits of the aborigines, I could collect little information, as only a collective number of about 100 men, a few women and children, were seen, in small scattered parties; but, judging from the number of encampments seen, at least a thousand must visit the banks of the river; and it is probable that the whole of the inhabitants for at least 100 miles on each side are dependent on it for water during the dry season. Neither s.e.x wear any clothing. Their weapons and utensils are similar to those used on the eastern coast; nor was there any characteristic by which they could be observed to differ from the aborigines of other portions of Australia. Fish, rats, gra.s.s seeds, and a few roots, const.i.tute their chief food. On the upper part of the river they bury their dead, piling wood on the grave; near the junction of the Thompson they suspend the bodies in nets, and afterwards remove the bones; while on Cooper's Creek the graves are mounds of earth three to four feet high, apparently without any excavation, and surmounted by a pile of dead wood. In the last-named locality the number of burial mounds which had been constructed about two years ago greatly exceed the proportion of deaths which could have possibly occurred in any ordinary season of mortality, even a.s.suming the densest population known in any other part of Australia; and it is not improbable that the seasons of drought which proved so destructive to the tree vegetation higher up the river may have been equally disastrous in its effects on the aboriginal inhabitants of this portion of the interior.

A.C. GREGORY.

Sydney, 27 August, 1858.