THE SPINNING-TOP “ASLEEP.”
Spin a top, and it will for some time stand “asleep,” as it is called in the parlance of the play-ground. The cause is thus explained by Dr. Arnot, in his valuable Elements of Physics: “While the top is perfectly upright, its point being directly under its centre, supports it steadily, and although turning so rapidly, has no tendency to move from the place; but, if the top incline at all, the side of the peg, instead of the very point, comes in contact with the floor, and the peg then becomes a little wheel or roller, advancing quickly, and, with its touching edge, describing a curve somewhat as a skater does, until it becomes directly under the body of the top, as before. It thus appears that the very fact of the top inclining causes the point to shift its place, so that it cannot rest until it come again directly under the centre of the top.”