The moon, possessing no native light, shines entirely by light received from the sun, and which is reflected to us from her surface. That half of her which is towards the sun is enlightened, and the other half is dark and invisible: hence, when she is between us and the sun, she disappears, because her dark side is then towards us. Whilst making her revolution round the heavens, she undergoes a continual change of appearance. She is sometimes on our meridian at midnight, and therefore in that part of the heavens which is opposite to the sun; when she appears with a face completely circular, which is called a _full moon_. As she moves eastward, a part of her dark side comes forward on the western side, and, in a little more than seven days, reaches to the meridian, at about six in the morning, having the appearance of a semi-circle, with the convex side turned towards the sun: this crescent gradually becomes more slender, till, about fourteen days after the full moon, being so near the sun, and in a line between that luminary and our earth, she is rendered invisible to us, from the superior splendor of that orb of light. About four days after this disappearance, she may be seen in the evening, a little to the eastward of the sun, in the form of a fine crescent,[121] as before, but having her convex side turned from the sun. Travelling still towards the east, the crescent becomes wider; and when advanced to the meridian, about six in the evening, she again bears the appearance of a bright semi-circle, with the same difference that we observed of the crescent, that is, its convex side is now turned _from_ the sun. Advancing still more eastward, the semi-circular moon widens into an oval shape, till at last, in about twenty-nine days and a half from the last opposition to the sun, she is again in the same situation, and appears a full moon. The following account of the _harvest moon_, so called, taken from the Pantalogia, will no doubt be acceptable to the reader.--It is remarkable that the moon, during the week in which she is full about the time of harvest, rises sooner after sun-setting than she does in any other full moon week in the year. By this means, she affords an immediate supply of light after sun-set, which is very beneficial for the harvest and gathering in the fruits of the earth; and hence this full moon is distinguished from all the others in the year, by calling it the harvest-moon.