The Last Expedition

PECULIARITY OF THE DARLING

SUDDEN FLOODS TO WHICH IT IS SUBJECT

CHARACTER OF THE MURRAY

ITS PERIODICAL RISE

BOUNTY OF PROVIDENCE

GEOLOGICAL POSITION OF THE TWO RIVERS

OBSERVATIONS

RESULTS

SIR THOMAS MITCHELL'S JOURNEY TO THE DARLING

ITS JUNCTION WITH THE MURRAY

ANECDOTE OF MR. SHANNON

CAPTAIN GREY'S EXPEDITION

CAPTAIN STURT'S JOURNEY

MR. EYRE'S SECOND EXPEDITION

VOYAGE OF THE BEAGLE

MR. OXLEY'S OPINIONS

STATE OF THE INTERIOR IN 1828

CHARACTER OF ITS PLAINS AND RIVERS

JUNCTION OF THE DARLING

FOSSIL BED OF THE MURRAY

FORMER STATE OF THE CONTINENT

THEORY OF THE INTERIOR.

The Australian continent is not distinguished, as are many other continents of equal and even of less extent, by any prominent geographical feature. Its mountains seldom exceed four thousand feet in elevation, nor do any of its rivers, whether falling internally or externally, not even the Murray, bear any proportion to the size of the continent itself. There is no reason, however, why rivers of greater magnitude, than any which have hitherto been discovered in it, should not emanate from mountains of such limited altitude, as the known mountains of that immense and sea-girt territory. But, it appears to me, it is not in the height and character of its hilly regions, that we are to look for the causes why so few living streams issue from them. The true cause, I apprehend, lies in its climate, in its seldom experiencing other than partial rains, and in its being subject to severe and long continued droughts. Its streams descend rapidly into a country of uniform equality of surface, and into a region of intense heat, and are subject, even at a great distance from their sources, to sudden and terrific floods, which subside, as the cause which gave rise to them ceases to operate; the consequence is, that their springs become gradually weaker and weaker, all back impulse is lost, and whilst the rivers still continue to support a feeble current in the hills, they cease to flow in their lower branches, assume the character of a chain of ponds, in a few short weeks their deepest pools are exhausted by the joint effects of evaporation and absorption, and the traveller may run down their beds for miles, without finding a drop of water with which to slake his thirst.

In illustration of the above, I would observe that during the progress of the recent expedition up the banks of the Darling, and at a distance of more than 300 miles from its sources, that river rose from a state of complete exhaustion, until in four days it overflowed its banks. It was converted in a single night, from an almost dry channel, into a foaming and impetuous stream, rolling along its irresistible and turbid waters, to add to those of the Murray.

There can be no doubt, but, that this sudden rise in the river, was caused by heavy rains on the mountains, in which its tributaries are to be found, for the Darling does not receive any accession to its waters below their respective junctions, of sufficient magnitude to account for such an occurrence. [Note 1. below]

[Note 1. The principal tributaries of the Darling, are the Kindur, the Keraula, the Namoy, and the Gwydir. They are beautiful mountain streams, and rise in the hilly country, behind Moreton Bay, in lat. 27 degrees, and in longitude 152 degrees E.]

When, on the return of the expedition homewards the following year, some two months later in the season than that of which I have just been speaking, Oct. 1844, there had been no recurrence of the flood of the previous year, but the Darling was at a still lower ebb than before, and every lagoon, and creek in its vicinity had long been exhausted and waterless. [Note 2. below] Now, it is evident, as far as I can judge, that if the rains of Australia were as regular as in other countries, its rivers would also be more regular in their flow, and would not present the anomaly they now do, of being in a state of rapid motion at one time, and motionless at another.

[Note 2. It may be necessary to warn my readers that a creek in the Australian colonies, is not always an arm of the sea. The same term is used to designate a watercourse, whether large or small, in which the winter torrents may or may not have left a chain of ponds. Such a watercourse could hardly be called a river, since it only flows during heavy rains, after which it entirely depends on the character of the soil, through which it runs, whether any water remains in it or not.]

A lagoon is a shallow lake, it generally constitutes the back water of some river, and is speedily dried up. In Australia, there is no surface water, properly so called, of a permanent description.]

But, although I am making these general observations on the rivers, and to a certain extent of climate of Australia, I would not be understood to mean more than that its seasons are uncertain, and that its summers are of comparatively long duration.

In reference to its rivers also, the Murray is an exception to the other known rivers of this extensive continent. The basins of that fine stream are in the deepest recesses of the Australian Alps--which rise to an elevation of 7000 feet above the sea. The heads of its immediate tributaries, extend from the 36th to the 32nd parallel of latitude, and over two degrees of longitude, that is to say, from the 146 degrees to the 148 degrees meridian, but, independently of these, it receives the whole westerly drainage of the interior, from the Darling downwards. Supplied by the melting snows from the remote and cloud-capped chain in which its tributaries rise, the Murray supports a rapid current to the sea. Taking its windings into account, its length cannot be less than from 1300 to 1500 miles. Thus, then, this noble stream preserves its character throughout its whole line. Uninfluenced by the sudden floods to which the other rivers of which we have been speaking are subject, its rise and fall are equally gradual. Instead of stopping short in its course as they do, its never-failing fountains have given it strength to cleave a channel through the desert interior, and so it happened, that, instead of finding it terminate in a stagnant marsh, or gradually exhausting itself over extensive plains as the more northern streams do, I was successfully borne on its broad and transparent waters, during the progress of a former expedition, to the centre of the land in which I have since erected my dwelling.

Sunset on the Murray

As I have had occasion to remark, the rise and fall of the Murray are both gradual. It receives the first addition to its waters from the eastward, in the month of July, and rises at the rate of an inch a day until December, in which month it attains a height of about seventeen feet above its lowest or winter level. As it rises it fills in succession all its lateral creeks and lagoons, and it ultimately lays many of its flats under water.

The natives look to this periodical overflow of their river, with as much anxiety as did ever or now do the Egyptians, to the overflowing of the Nile. To both they are the bountiful dispensation of a beneficent Creator, for as the sacred stream rewards the husbandman with a double harvest, so does the Murray replenish the exhausted reservoirs of the poor children of the desert, with numberless fish, and resuscitates myriads of crayfish that had laid dormant underground; without which supply of food, and the flocks of wild fowl that at the same time cover the creeks and lagoons, it is more than probable, the first navigators of the Murray would not have heard a human voice along its banks; but so it is, that in the wide field of nature, we see the hand of an over-ruling Providence, evidences of care and protection from some unseen quarter, which strike the mind with overwhelming conviction, that whether in the palace or in the cottage, in the garden, or in the desert, there is an eye upon us. Not to myself do I accord any credit in that I returned from my wanderings to my home. Assuredly, if it had not been for other guidance than the exercise of my own prudence, I should have perished: and I feel satisfied the reader of these humble pages, will think as I do when he shall have perused them.