Sunday, 29th April, Gum Creek under Mount Denison. Latitude, 21 degrees 48 minutes. Variation, 3 degrees 20 minutes east. Mount Denison and the surrounding hills are composed of a hard reddish-brown sandstone. About one hundred yards from the summit is a course of conglomerate, composed of stones from half an inch to four inches in diameter, having the appearance of being rounded at a former period by water. From the foot to the top of this course is about ten feet, and the breadth on the top is about twelve feet. There is red sandstone on the summit, with three or four pines growing. The mount and adjoining hill are covered with spinifex, but the plain is grassed. The wind has now changed to the west, and it is much hotter.