Procuring the necessary observations completed the duties of the day; but, alas! the sleep all could have enjoyed so much after our work, was rendered impossible by the swarms of mosquitoes, who at sunset relieved those of their tribe upon whom the day duty had devolved, and commenced a most unsparing attack upon us: all devices to escape them were tried in vain, and some of the men were really half mad with the insufferable annoyance: at last, about eight o'clock, when all patience seemed exhausted, a welcome peal of thunder, and bright flashes of lightning announced the expected and much desired squall. It served to blow away some of our persecutors; but our rest was of very short duration, and I was at length compelled to order the people to take to the boats, fairly driven from the shore by our diminutive but invincible assailants. The tide set past the boats at the rate of four knots per hour, and it fell 33 feet, being 6 feet more than we had as yet found it. The only rock seen here was a block, visible at low-water; it was a conglomerate, and the most southerly formation of the kind we met with. THE FLOOD-TIDE. February 26. The daylight found us all anxiously speculating upon the probable results to be accomplished before the darkness once more closed in upon us, but the morning being perfectly calm, we were compelled to wait till the flood-tide made: this soon took us past an island four miles from the eastern shore, seen the evening before, and which now proved to be a narrow strip, covered with the never-failing mangrove; and having two smaller islands, nearly identical in character, lying two miles south of it. We passed them at noon, and saw the land to the westward, our position being then 20 miles south of Point Torment. The water had shoaled in several places during the passage to less than a fathom (low-water); but the tide hemmed in by the contraction of this great inlet (the left shore of which gradually trending to the eastward, here approached to within six miles of the opposite coast) still hurried us on with a rapidity agreeable enough but not quite free from danger, towards what appeared to be the mouth of a large river. If our exultation had been great in the morning, when such success as this was only half anticipated, what was it at that exciting moment when the eventful hour which should give us the triumph of such a discovery as that we now fairly anticipated, seemed within our grasp? I cannot answer for others, but for myself I had never known a sensation of greater delight. Doubt, disappointment, difficulty, and danger; all, all were unheeded or forgotten in the one proud thought that for us was reserved an enterprise the ultimate results of which might in some future year affect the interests of a great portion of the world! Presently, as if to recall to their routine of duty, these upward-springing thoughts, the boats were found to be rapidly carried by the stream towards an extensive flat,