The same observations apply to _magnitude_ and _distance_. Objects of gigantic magnitude, as, for instance, the pyramids of Egypt, at first appear less than they are in reality; and it is only by admeasurement, examination, and comparison, that the mind becomes impressed with the idea of their immensity. A building, the details of which are in just harmony, always appears to be smaller than it is, because no discordance betrays the vast preponderance of certain parts over the littleness of others. Habit, or, in other words, education, is essentially requisite to aid the eye in its appreciation of magnitude. We may say the same with respect to _distance_. An infant does not distinguish between near and distant objects; its eyes have yet to become educated, and so have those of adults placed in circumstances to which they are unaccustomed. For example, the walls of a city, reared in a vast level plain, and descried at a distance, appear to be far nearer than the traveller will find them to be; again, when standing on the beach, we look at a ship in the distance, we are apt to think it closer to the shore than we should prove it to be were we to traverse the distance in a boat. A sailor would judge of the distance accurately. How much the accuracy and utility of the eye depend upon practice or education may be illustrated by the case of a boy, who, as described by Cheselden, was born quite blind, but was suddenly restored to sight, at the age of twelve, by the skilful removal of the cataract. At first, he was impressed with the idea that all the objects which he saw around him touched his eyes, in the same manner as in the act of touch they came in contact with the skin. He could neither estimate distance, nor distinguish one object from another, until he had applied the test of touch as a corrective and assistant.