Mr. A. "I do not wonder at your surprise, since many philosophers have been much perplexed to account for the same appearance. It is not uncommon to find great quantities of shells and relics of marine animals even in the bowels of high mountains, very remote from the sea. They are certainly proofs that the earth was once in a very different state from what it is at present. When you study geology you will know more on this subject."
William. "I got to the high field next our house, just as the sun was setting, and I stood looking at it till it was quite lost. What a glorious sight! The clouds were tinged with purple and crimson and yellow of all shades and hues, and the clear sky varied from blue to a fine green at the horizon. But how large the sun appears just as it sets! I think it seems twice as big as when it is overhead."
Mr. A. "It does so; and you may probably have observed the same apparent enlargement of the moon at its rising."
William. "I have; but pray what is the reason of this?"
Mr. A. "It is an optical deception, depending upon principles which I cannot well explain to you till you know more of that branch of science. But what a number of new ideas this afternoon's walk has afforded you! I do not wonder that you found it amusing; it has been very instructive, too. Did you see nothing of all these sights, Robert?"
Robert. "I saw some of them, but I did not take particular notice of them."
Mr. A. "Why not?"
Robert. "I don't know. I did not care about them, and I made the best of my way home."
Mr. A. "That would have been right if you had been sent with a message; but as you only walked for amusement, it would have been wiser to have sought out as many sources of it as possible. But so it is one person walks through the world with his eyes open, and another with them shut; and upon this difference depends all the superiority of knowledge the one acquires above the other. I have known sailors who had been in all the quarters of the world, and could tell you nothing but the signs of the tippling-houses they frequented in the different ports, and the price and quality of the liquor. On the other hand, a Franklin could not cross the Channel,[D] without making some observations useful to mankind. While many a vacant, thoughtless youth is whirled throughout Europe without gaining a single idea worth crossing a street for, the observing eye and inquiring mind find matter of improvement and delight in every ramble in town or country. Do you, then, William, continue to make use of your eyes; and you, Robert, learn that eyes were given you to use."