September 24.--At eight o'clock the horses began to ascend the mountain, and it was twelve before we reached the summit, a distance of exactly two miles. How the horses descended I scarcely know; and the bare recollection of the imminent dangers which they escaped, makes me tremble. At one period of the descent, I would willingly have compromised for a loss of one third of them, to ensure the safety Of the remainder. It is to the exertions and steadiness of the men, under Providence, that their safety must be ascribed. The thick tufts of grass and the loose soil also gave them a surer footing, of which the men skillfully availed themselves. The length of the descent was two measured miles and three quarters, and upon first, an angle of depression of 40 degrees for one thousand two hundred and fifty-four feet: we then slightly ascended 4 or 6 degrees for four thousand six hundred and twenty, and from thence the descent, in a continued straight line, to the run of water at the base, was on the various angles of 28, 32, 35, 40, and 46 degrees, eight thousand five hundred and eighty feet; from whence I deduce the perpendicular height to be nearly six thousand feet, which is certainly underrated. The descent terminated in a very narrow steep valley, down which we proceeded for near three quarters of a mile, when the small stream before mentioned joined a very considerable one seen yesterday from Sea View Mount; and the valley opening, we halted on the banks of the river on a spot which afforded us plenty of excellent grass, and was in other respects favourable for that rest which the horses required before they could resume their journey. One of the horses when about a third down the mountain was quite incapable of proceeding, we therefore were obliged to leave him for the night, with the loads of two other horses. It was past four o'clock before we arrived at our halting-place, having been exactly three hours and a half in descending. September 25.--Despatched the men to bring down the horse and the baggage left on the mountain yesterday. They returned in the afternoon with both, but the horse was scarcely able to stand. In the course of the day examined the valley a few miles, when we found that it opened considerably four or five miles down; the hills previously thereto being very steep, but covered with grass, and abounding with kangaroos. It was therefore determined to move farther down the river to-morrow, instead of remaining here two days as originally proposed. In the present reduced state of the horses, we were obliged to make short stages with frequent halts, in hopes of sufficiently recruiting their strength so as to proceed with greater expedition along the coast.