Moon
the single satellite attendant on the earth. Its diameter is 2,160 miles, that of the earth (which is 7,918) being nearly four times as great. Its superficial extent is about a 13th part of the earth's surface; its bulk is 1-45 that of the earth, but as the earth is relatively heavier, its weight is about 80 times that of the moon. As the moon revolves around the earth it manifests phases. After absence for a few nights it reappears as a delicate crescent of white light in the W. sky after sunset. Night after night it moves farther to the E., the illuminated portion of its disk continually increasing till the moon becomes full and rises about sunset. When the light of the moon has again so diminished that it is in its last quarter, it is seen high in the heavens in the morning. When it becomes full, the sun and the earth are so nearly in MOOR across, so is Aristotle, Theophilus is 64, and Petavius 78. Some are 16,000 and 17,000 feet deep. From the absence of an atmosphere the moon must be uninhabitable by any life analogous to that with which we are acquainted.