I endeavoured to ascertain what had been the amount of wastage, but I could arrive at no satisfactory conclusion. I sounded the cask, by striking it in different places with the butt end of my knife, but I derived little knowledge from this. The creaking of the ship's timbers, and the rush of the waves, prevented any observation of this kind from being definite or accurate. I fancied that the blows gave back a very hollow sound, as if a large space within was empty. If it were a fancy, it was far from being a pleasant one; and I gave over my "soundings" with a considerable feeling of uneasiness. Fortunately the tap was a very small hole, and the jet from it of no great thickness. As near as I could tell by the touch, and from the repeated application I had made to it with my lips, this could not have been over the thickness of my little finger, which at that time was not of much greater circumference than a goose's quill. I knew that such a tiny stream would be a long while in spending the contents of so large a tank; and I endeavoured to recall to mind how long it might have been since I last drank. In this, however, I was not successful. It seemed but a short while to me, but excited as I had been, and confused in my ideas, it might have been an hour, or even more. I was completely baffled in any calculation that I attempted. I remained for a considerable time, pondering upon some scheme by which I might determine the quantity of water that still remained in the cask, for about this I was now most anxious. Only one hour before, food had been the source of my uneasiness; before that it had been drink; and now once more drink was my trouble, for of meat I had a plenty. I remembered having heard that brewers, coopers, and others whose business lies among the great wine vaults of the docks, had a way of telling pretty nearly the contents of a barrel of liquid, without submitting them to actual measurement, but I had not heard how they managed the matter. I regretted not having been told. I thought of a plan by which I could have ascertained, to a nicety; but I lacked the proper instrument to put it in execution. I understood enough of hydraulics to know that water will rise to its own level if guided by a pipe or tube; I knew, therefore, that if I had only possessed a piece of hose, I could have attached it to the tap-hole, and thus discovered how high the water stood in the cask. But where was the hose or other pipe to be had? Of course I could not get at what I desired in this way, and I relinquished the idea without giving it farther consideration. Just at this moment a better plan suggested itself, and I proceeded to put it in execution. It was so simple, I wondered I had not thought of it before. It was neither more nor less than to cut another hole through the staves, higher up, and if need be another, and so on, until I reached a point where the water ceased to run. This would give me the knowledge I wanted.