The Study of Astronomy, adapted to the capacities of youth / In twelve familiar dialogues, between a tutor and his pupil: explaining the general phænomena of the heavenly bodies, the theory of the tides, &c.

by teacher of astronomy John Stedman

Pupil. And yet she appears as far distant as the sun.

Tutor. You are now, I hope, convinced of what I said relative to distant objects.

Pupil. I am, Sir: and I suppose the reason of the moon’s appearing as large as the sun, is because she is so much nearer to us.

Tutor. It is so.—For, at a total eclipse of the sun, which happens when the moon is in a right line between the sun and the earth, the sun is obscured from our sight, although his disc is 160 thousand times as large as that of the moon. In like manner would the moon, when at full, be hid by placing your cricket-ball in a line between your eye and her, yet, you know, the ball is not so large as the moon; but being nearer the eye, it is apparently so.

Pupil. This is very clear. But——

Tutor. I conjecture you were going to ask me to explain the nature of eclipses.

Pupil. That was certainly my intention, Sir.

Tutor. There are other things you must be made acquainted with before you will be able to comprehend it, and which I will endeavour to make you understand before we enter on the subject.

Pupil. Whenever you please, Sir.

Tutor. You have taken a view of the earth from the planet Venus.—Suppose I transport you to one of the planets belonging to another system; what description do you think you should give of it?