Should it ever fall to the lot of any of my readers to have to cook periwinkles--and there are many worse things, when you are certain of their freshness--let them remember that they should be boiled in 'salt water'. This is to give them toughness; if fresh water is used, however expert the operator may be with his pin, he will fail to extract more than a moiety of the curly delicacy. These little facts, though extraneous to our subject, are always worth knowing. At one end of Garden Island, and distant from it about 200 yards, stands a very singular rock, of a whitish hue, and when struck at a certain angle by the sun, so much resembling the canvas of a vessel, that it was named the "Sail Rock." At low tide this could be reached by wading, the water being little more than knee-deep. Its base was literally covered with oysters of the finest quality. The mere task of getting there was one of considerable difficulty, for the rock was as slippery as glass, and whenever you got a fall--which happened on an average every five minutes--bleeding hands and jagged knees bore testimony to a couch of growing bivalves being anything but as soft as a feather bed; also the oysters cling so fast that they might be taken for component parts of the rock, and only a cold chisel and mallet will induce them to relinquish their firm embrace. Three or four of the party had ventured out, and we had secured a large sackful, after which we all retired to the tent, except one of our number, who, having a lady-love in Cardwell with an inordinate affection for shell-fish, lingered to fill a haversack for his 'inamorata'. We were comfortably smoking our pipes and watching with satisfaction the tide rising higher and higher, when a faint "coo-eh" from the direction of the rock reached us, followed by another and another and another, each one more shrill than the last. "By Jove, Wordsworth's in some trouble!" exclaimed one of our party, and, snatching up our carbines, we hurried to the end of the island at which stood the Sail Rock. The tide had now risen considerably, and the water between the rock and ourselves was over four feet deep, and increasing in depth each moment. We saw poor Wordsworth clinging on to the slippery wall, as high up as the smooth mass afforded hand-hold. "Come along, old fellow!" we shouted; "it's not up to your neck yet." "He turned his head over his shoulder--even at the distance we were, its pallor was quite visible--and slowly and cautiously releasing one hand, he pointed to the water between himself and the island. "By Jove!" cried the pilot, "he's bailed up by a shark, look at his sprit-sail!" and following his finger we saw an enormous black fin sailing gently to and fro, as regularly and methodically as a veteran sentry paces the limits of his post.