On Mitchell’s return to Sydney, there being some doubt as to the point of outflow of the newly-discovered Victoria River, Kennedy was sent out with a small party to follow the river down and ascertain its course and destination.

On the 13th of August, he reached Mitchell’s lowest camp on the Victoria River, and started to trace the river down.  During the first day’s journey he came across some natives, from one of whom he learnt that the aboriginal name of the river was the Barcoo.  Two days afterwards he observed with some anxiety that the trend of the valley was inclining from northwards towards the point whence Sturt had turned back from his upward course on Cooper’s Creek.  As the second part of his instructions was to find a practicable road to the Gulf, he feared that he would not have sufficient provisions to fulfil both duties.  He therefore made a stationary camp, and with two men proceeded down the river.  But after two days’ journey, he found that the Barcoo turned to the west, and even north of west.  The channel now showed large reaches of water within its confines, some of them more than one hundred yards in width.  This induced him to alter his plan, and he thought he should follow such an important watercourse and ascertain its outflow.  He therefore turned back for the remainder of his party.  On the 30th of August he discovered a large river coming from the North-North-East, and he named it the Thomson.  With the usual inconsistency of Australian inland rivers, the Thomson soon presented another and different scene.  The great pastoral stretches of the upper course were left behind, and were succeeded by flat and inferior country intersected by sand-ridges.  The course of the river itself once more turned to the southward, and was but scantily watered.  Still Kennedy persevered until convinced that further progress must bring him to Sturt’s furthest on Cooper’s Creek.  The face of the land answered to Sturt’s description; and grass and feed both beginning to fail him, Kennedy had to consider whether it was worth while risking the lives of his men to confirm what was practically a certainty.  At last vistas of the desert, described by Sturt with such terrible fidelity, appeared stretching away to the horizon, and Kennedy turned back, satisfied that the Victoria River and Cooper’s Creek were one and the same stream.

It was now Kennedy’s intention to make an excursion towards the Gulf of Carpentaria.  On his way down, in order to travel lighter, he had buried a large quantity of flour and sugar as well as his drays.  When he arrived at the cache of provisions on his way back, he found that the natives had dug the rations up, and in mere wantonness had so mixed and scattered them as to render them useless.  A little further on, he was just in time to save the carts, for an aboriginal was probing in the ground with a spear to ascertain their whereabouts.  During this excursion Kennedy noticed that the blacks were given to “chewing tobacco in a green state;” but the “tobacco” was, of course, the pituri plant, which they are accustomed to masticate.  By the time he reached the head of the Warrego, Kennedy was too short of provisions to attempt his projected Gulf expedition, and had to make homeward, but resolved to go down by that river and ascertain whether it joined the Darling or flowed westward.