We had struck a bee-line southward some days before, and were now approaching the equator--the days not growing much cooler in consequence. One day, when we had got becalmed, the whole ship's company (almost) went in bathing, and a thrilling incident was the result. The captain, always glad to make the men happy, had caused the mainsail to be slung over the side, with either end upheld by the overhanging yards, the belly of the canvas making a long dip in the brine, thus making a delightful shallow for the more timid swimmers to exercise their talents in, while bolder spirits might strike out to any distance they pleased. A great peril was involved in this operation of mid-sea tropical bathing, on account of the sharks, which are always more or less numerous in the wake of a ship. Well, we all had an excellent time in the water, and were not in a hurry to come out. The captain had got tired of laughing at us, and had gone below for a siesta. Old Snollygoster, after having got through with his ablutions, was lazily watching us from the rail of the ship. He was probably as able a swimmer as ever lived. He now amused us with sundry suggestions and cautions with regard to sharks, warning us not to go too far from the ship, and solemnly averring that _his_ assistance need not be counted on, in event we were attacked. Several of us had swum to a considerable distance from the vessel, when suddenly some one sung out: "Sharks! sharks!" I thought it was a joke at first, but upon turning and casting a look seaward, I, sure enough, discovered several of the ominous black fins cutting water toward us.