Mrs. B. Because it is twenty-four hours and three-quarters before the same meridian, on our globe, returns beneath the moon. The earth revolves on its axis in about twenty-four hours; if the moon were stationary, therefore, the same part of our globe would, every twenty-four hours, return beneath the moon; but as during our daily revolution, the moon advances in her orbit, the earth must make more than a complete rotation, in order to bring the same meridian opposite the moon: we are three-quarters of an hour in overtaking her. The tides, therefore, are retarded, for the same reason that the moon rises later by three-quarters of an hour, every day.
We have now, I think, concluded the observations I had to make to you on the subject of astronomy; at our next interview, I shall attempt to explain to you the elements of hydrostatics.
Questions
1.(Pg. [108]) In what time does the moon revolve round the earth? what is the inclination of her orbit? and how does she accompany the earth?
2.(Pg. [108]) As the moon revolves round the earth, and also accompanies it in its annual revolution, in what form would you draw the moon's orbit?
3.(Pg. [109]) What causes the moon always to present the same face to the earth, and what must be the length of a day and night to its inhabitants?
4.(Pg. [109]) Can the earth be seen from every part of the moon, and will it always exhibit the same appearance?
5.(Pg. [109]) What are the changes of the moon called?
6.(Pg. [109]) How are these changes explained by [fig. 2. plate 11]?
7.(Pg. [109]) What is meant by her first quarter?