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then see the earth in the sky like a full moon, looking much larger than the moon looks to us. As the moon advances in its orbit day after day, this light diminishes, and about the time of first quarter disappears from our sight owing to the brightness of the illuminated portion of the moon.

Seven or eight days after the almanac time of new moon, the moon reaches its first quarter. We then see half of the illuminated disk. During the week following, the moon has the form called gibbous. At the end of the second week the moon is opposite the sun, and we see its entire hemisphere like a round disk. This we call full moon. During the remainder of its course the phases recur in reverse order, as we all know.

We might regard all these recurrences as too well known to need description, yet, in the Ancient Mariner, a star is described as seen between the two horns of the moon as though there were no dark body there to intercept our view of the star. Probably more than one poet has described the new moon as seen in the eastern sky, or the evening full moon as seen in the west.

We can see with the naked eye that the moon's surface is variegated by bright and dark regions. The latter are sometimes conceived to have a vague resemblance to the human face, the nose and eyes being especially prominent. Hence the "man in the moon." Through even the smallest telescopes we see that the surface has an immense variety of detail; and the more powerful the tele-