ing swiftly towards the earth, along the course of the rays. If we could accomplish the journey in an hour, the history of six thousand years would be condensed into that period. The schoolmen defined eternity as punctum stans, and the propagation of light gives a startling illustration of their meaning. We can arrest the flow of time by continued motion. Suppose our world is the illuminated dial of a clock, that the hand is at twelve o'clock, and that the machinery is faithfully doing its duty; we have only to take up our position in a star that moves from the earth as rapidly as the rays from the dial, in order to arrest the hand for ever at that hour. To one who is stationary, the hand makes its ordinary revolution; but one who moves away with the rapidity of light, sees it perfectly fixed. Nay, it is possible to turn back the hand, as in the case of the dial of Ahaz. In a star moving away from the earth more rapidly than the light, a person would see the hands gradually move in the reverse order, from twelve to eleven o'clock, and so on. By moving in the direction opposite to that of the light, centuries might be concentrated into hours, and hours into seconds. Had we unlimited powers of locomotion, we would not be under the necessity of reading unintelligible and prosaic accounts of campaigns and battles in the past history of our country; it would only be necessary to wing our way to some star where the light from the seat of war is
