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?
R. I saw some of them, but I did not take particular notice of them.
Mr. A. Why not?
R. 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 of 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 man 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 quarters of the world, and could tell you nothing but the signs of the tippling-houses they frequented in different ports, and the price and quality of the liquor. On the other hand, a Franklin could not cross the channel 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.