While the boat’s crew rested and filled their baricas, I ascended the rocks over which the water was falling and was surprised to find its height had been so underrated when we passed by it last year:  it was then thought to be about forty feet, but I now found it could not be less than one hundred and fifty.  The rock, a fine-grained siliceous sandstone, is disposed in horizontal strata, from six to twelve feet thick, each of which projects about three feet from that above it, and forms a continuity of steps to the summit, which we found some difficulty in climbing; but where the distance between the ledges was great we assisted our ascent by tufts of grass firmly rooted in the luxuriant moss that grew abundantly about the water-courses.  On reaching the summit, I found that the fall was supplied from a stream winding through rugged chasms and thickly-matted clusters of plants and trees, among which the pandanus bore a conspicuous appearance and gave a picturesque richness to the place.  While admiring the wildness of the scene, Mr. Montgomery joined me; we did not however succeed in following the stream for more than a hundred yards, for at that distance its windings were so confused among rocks and spinifex that we could not trace its source.  After collecting for Mr. Cunningham, who was confined on board by sickness, a few specimens of those plants which, to me, appeared the most novel, we commenced our descent, and reached the bottom in safety; by which time the tide was ebbing so rapidly that we set off immediately on our return with a view of arriving on board by low-water, in order that no time might be lost in sending the boats up with our empty water-casks.

During our absence Mr. Roe, who was fast recovering from the effects of his fall, had obtained the sun’s meridional altitude upon the islet at the entrance of the river, which gave 15 degrees 25 minutes 46 seconds for its latitude, differing from the plan of last year by only fifteen seconds.

July 27.

The following day the boats were despatched up the river, but as the ebb-tide ran until after four o’clock it was late at night before they reached the cascade, having experienced some delay by running upon the sandbanks, which, above Alligator Island, are very numerous and form a narrow winding channel of not more than twelve feet deep; these banks are dry at low-water, and are composed of a yellow quartzose sand.  At midnight, as soon as the launch and cutter were loaded, for it did not take more than half an hour to fill the casks, I despatched them to the vessel with orders to return the following night for another load, and in the meantime I purposed continuing the examination of the river, of which we knew nothing beyond a few miles above the cascade.

July 28.

We were, however, unable to set out until half flood the next morning, on account of the shoalness of the channel.

For ten miles we found little or no variation either in its character or course:  its windings were only just sufficient to intercept a clear view; for so direct was its course, that from this part the high round hill near the entrance was seen midway between the hills that form the banks of the river.