I was about to signal to be drawn up, when above me I saw what appeared to be a flash of darkness, coming down through the well. With a rush and a swirl it entered the cavern, and in a moment I recognised the fact that a great fish was swooping around and about me. Its movements were so rapid and irregular, now circling along the outer edge of the floor of the cavern, then mounting above me, until its back seemed to scrape the roof, that I could not form a correct idea of the size of the creature. It seemed to me to be at least twenty feet long. I stood almost stupefied, keeping my eyes as far as possible fixed upon the swiftly moving monster. Sometimes he came quite near me, when I shuddered in every fibre, and then he shot away, but ever gliding with powerful undulations of his body and tail, around, about, and above me. I did not dare to signal to be drawn up, for fear that the terrible creature would enter the well-hole with me. Then he would probably touch me, perhaps crush me against the wall, but my mind was capable of forming no plans; I only hoped the fish would ascend and disappear by the way he came. [Illustration: "I STOOD STUPEFIED."] My mind was not in its strongest condition, being much upset by a great trouble, and I was so frightened that I really did not know what I ought to do, but I had sense enough left to feel sure that the fish had been attracted into the cavern by my lamp. Obviously the right thing to do was to extinguish it, but the very thought of this nearly drove me into a frenzy. I could not endure to be left alone with the shark in darkness and water. It was an insane idea, but I felt that, whatever happened, I must keep my eyes upon him. Now the great fish began to swoop nearer and nearer to me, and then suddenly changing its tactics, it receded to the most distant wall of the cavern, where, with its head toward me, it remained for the first time motionless. But this did not continue long. Gently turning over on its side, it opened its great mouth, and in an instant, with a rush, it came directly at me. My light shone full into its vast mouth, glistening with teeth, there was a violent jerk which nearly threw me off my feet, and all was blackness. The shark had swallowed my lamp! By rare good fortune he did not take my hand also. Now I frantically tugged at my signal rope. Without my lamp, I had no thought but a desire to be pulled out of the water, no matter what happened. In a few minutes I sat divested of my diving suit, and almost insensible upon the deck of the schooner. As soon as I was able to talk I told my astonished comrades what had happened, and while we were discussing this strange occurrence, one of them, looking over the side, saw, slowly rising to the surface, the body of a dead shark. [Illustration: "IT WAS A PINT BOTTLE."]