CAPTAIN S.’S PEG PUZZLE.
One bright summer morning, which seems but a short while ago, unless I stop and count the years that have passed since then, we children were invited to take a sail across the bay with one of the kind-hearted old captains who owned a trim little cat-boat, which her owner was wont to boast would beat any other craft of her length in the harbor. But there was not much chance of beating anything on the morning of which I write, for, although a light northerly breeze was stirring when we intended to start, the girls of our party took so much time in which to get ready, that by the time we were fairly under way we were scarcely able to fill our sail. However, we managed to make some little headway, and in the course of two hours reached the beautiful rocky point covered with its grove of fine old trees, which, but for the delay in starting, would have been reached much earlier in the day. This point was quite a favorite spot for excursionists, and was hailed with delight by most of our party. We boys, however, cared more for the little Sea Dog, and the companionship of old Captain S., than for the walks on shore. So, claiming our full share of the good things packed in the baskets stowed away in the cabin, we decided to remain on board and share our picnic with the captain on the bay.
After all were on shore, and the hampers had been taken to the grove, we hoisted the sail and made for deeper water; but there was no wind, and we had to content ourselves with looking at the glassy surface around us, and feeling that we were in a boat away from shore, even if not in rapid motion. We ate our lunch as we listened to a delightful story told by the captain, of how his ship was once chased by a pirate, and only escaped through the timely interposition of a snow-storm. We next tried our hands at the oars and rowed some distance further from the land. Finally, as we were about to return for the others of our party on shore, a small piece of wood Fred found on the cabin floor changed the current of our thoughts, and we saw for the first time the little device I am about to describe. This bit of wood which he had picked up was a thin strip of a cigar-box cover. In one end was a circular hole about an inch in diameter, in the middle was a square hole of the same diameter, and at the extreme end was still another opening, in the form of an isosceles triangle, the perpendicular being of the same length as the side of the square.
When Captain S. saw the piece of wood he challenged us each to make one peg which should exactly fit all three holes. “But it can’t be done, Captain,” we both exclaimed at once; “the holes that have corners couldn’t be fitted with a round peg, and the peg large enough for the square would be too large for the triangle,” continued Fred, as he examined the openings more carefully. “But it can be done,” answered Captain S., with a peculiar kind of chuckle he always gave when very much pleased. “It can be done, for I have done it hundreds of times.”
He had done it hundreds of times; had made one peg which should fit a round, a square, and a triangular hole, and fit them nicely! How was it to be done? We thought it over, and tried to study it out; we even took out our jackknives and whittled away at an old broken thole-pin which lay in the bottom of the boat. But we couldn’t make it work; there were always the corners to be filled, and little spaces would be left if we tried to compromise, and make the pin less round as it increased in length; then the triangle! that wouldn’t accommodate itself to any shape we could devise. We whittled away for over an hour, now and again receiving a little encouragement from the captain, who greatly enjoyed our successive failures. During the meantime a brisk south-west wind had sprung up, and we were bounding over the water at a delightful speed; but we paid little attention to the sail; in fact, we hardly knew we were moving at all, so intent had we become to solve the mystery. After the others of the party came on board, we soon fired them with our enthusiasm, and every bit of available wood and every jackknife was brought into use. But not one of the party was bright enough to hit upon the right shape. I shall never forget the fun made of us by the girls—not one of whom, by the way, could sharpen a lead-pencil decently—when the captain finally showed us how the thing was done. Asking one of the older boys to take the helm, he picked up a bit of wood we had thrown aside as too small, whipped out his jackknife, and in less time than it takes me to write it, had the peg made and fitted to the holes. How he made it fit so well in so short a time has never ceased to be a source of wonder to me; but probably the practice of years, while off on lonely whaling cruises, had something to do with his dexterity.
He first whittled out a cylinder, which exactly fitted the circular hole; then he cut it off, so that its length should be the same as the diameter of the square (see Fig. 2). Now, by putting this sideways into the square opening, it fitted it perfectly. Lastly, leaving the base of the cylinder undisturbed, he cut away from either side until he had a shape like Fig. 3, which, when looked at from another point, presents the appearance of Fig. 4, and would, of course, perfectly fit the last and triangular opening.
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