Mr Barlow.—Might not the earth then at least appear as small as the sun or moon does?
Tommy.—I can hardly conceive that, and yet I see it would appear less and less the farther we went.
Mr Barlow.—Do you remember what happened to you when you left the island of Jamaica?
Tommy.—Yes, I do. One of the blacks held me upon the deck, and then I looked towards the island, and I thought that it began to move away from the ship, though in reality it was the ship moving away
from the land; and then, as the ship continued sailing along the water, the island appeared less and less. First, I lost sight of the trees and houses that stood on the shore; and then I could only see the highest mountains; and then I could scarcely see the mountains themselves; and at last the whole island appeared only like a dark mist above the water; and then the mist itself disappeared, and I could see nothing but a vast extent of water all round, and the sky above.
Mr Barlow.—And must not this be exactly the case if you could rise up into the air, higher and higher, and look down upon the earth?
Tommy.—Indeed it must.
Mr Barlow.—Now, then, you will be able to answer the question I asked you a little while ago: Could a person travel straight forward from the earth to the sun, how would they both appear to him as he went forward?
Tommy.—The earth would appear less and less as he went from it, and the sun bigger and bigger.
Mr Barlow.—Why, then, perhaps it would happen at last that the sun appeared bigger than the earth.