KOSMICOS. You are aware that there is a physical explanation of this phenomenon which accounts for it without the special design. This explanation is that the moon was once in a partially fluid state, and that she rotated on her axis in a period different from the present one. In such a condition, the attraction of the earth would produce great tides in the fluid substance of the moon; this attraction, combined with the centrifugal force of the moon's rotation on her own axis, would cause a friction, and this friction would retard the rate of her axial rotation, until it became coincident with the rate of her revolution around the earth. It is highly improbable that the moon was originally set in rotation on her axis with just the same velocity with which she was made to revolve around the earth. This improbability is based on the ellipticity of the moon's orbit, which is caused by the attraction of the sun. The mean distance of the moon from the earth is 240,300 miles; her smallest possible distance is 221,000 miles; and the greatest possible distance is 259,600. The usual oscillation between these extremes is about 13,000 miles on each side of the mean distance of 240,300. The diameter of the moon is 2,160 miles, or less than two sevenths of the earth's diameter. In volume she is about one fiftieth as large as the earth, but her density, or the specific gravity of her material, is supposed to be a little more than half of that of our globe; and her weight is about three and a half times the weight of the same bulk of water. When she is nearest to the sun, the superior attraction of that body tends to draw her out of her circular orbit around the earth; when she is farthest from the sun, this attraction is diminished, and thus her terrestrial orbit becomes slightly elliptical. But there is another attraction to be taken into account. This other attraction, in her former fluid condition, has given her the shape, not of a perfect sphere, but of an ellipsoid, or an elongated body with three unequal axes. The shortest of her axes is that around which she rotates; the next longest is that which points in the direction in which she is moving; and the longest of all points toward the earth. This shape of the moon, resulting from the earth's attraction, has been produced by drawing the matter of the moon which is nearest to the earth toward the earth, and by the centrifugal force which tends to throw outward the matter farthest from the earth. The substance of the moon being a liquid, so as to yield freely, she would be elongated in the direction of the earth. But if she was originally set in motion on her own axis at precisely the same rate with which she was made to revolve around the earth, the correspondence between the two motions could not have been kept up; her axial rotation would have varied, by reason of the fact that her relative distance from the sun and the earth varies with the ellipticity of her orbit around the