Tommy.—Because I see them move every night.
Mr Barlow.—But how are you sure that it is the stars which move every night, and not the earth itself?
Tommy considered, and said, "But then I should see the earth move, and the stars stand still."
Mr Barlow.—What, did you never ride in a coach?
Tommy.—Yes, sir, very often.
Mr Barlow.—And did you then see that the coach moved, as you sat still, and went along a level road?
Tommy.—No, sir; I protest I have often thought that the houses and trees, and all the country, glided swiftly along by the windows of the coach.
Mr Barlow.—And did you never sail in a boat?
Tommy.—Yes, I have; and I protest I have observed the same thing; for I remember I have often thought the shore was running away from the boat, instead of the boat from the shore.
Mr Barlow.—If that is the case, it is possible, even though the earth should move, instead of the stars, that you might only see what you do at present, and imagine that the earth you are upon was at rest.