the axes of the two eyes, by an instantaneous and unconscious movement of the orbits, as to make them meet in the same focus:whenever this adjustment does not take place, we see a nearer object double. Now a child, because he has only very recently acquired the habit of so adjusting the axes of the eyes, is conscious of a something wrong, when, in looking at a picture, he finds that the church on a distant hill, to be seen distinctly, instead of requiring an altered inclination of the orbits, must be looked at with the same angular direction of the eyes that serves for the dogs and horses on the foreground. This contradiction of the habit he has so lately acquired, not merely perplexes him, but produces a general confusion of objects, so as to prevent his receiving any vivid pleasure from the representation. It is obvious, moreover, that a good picture, which really looks like nature, will shock the visual habit more than an inferior one. An adult has learned how to look at objects which he knows to lie all on the same surface; nevertheless, the very same inconvenience is felt, even by adults, in looking at a panorama; for in this case the deception, being sometimes very perfect, we forget, for a moment, that it is a picture we are looking at; and, in attempting to adjust the eyes to the horizon, find the sight painfully strained.
It is however on another account, and for a more intellectual reason, that a child derives far more delight from a rude outline of familiar objects, than from a finished picture. As a general rule, drawings or engravings in black and white, are, by intelligent children, preferred to the same coloured; and an outline is preferred to a shaded drawing, and a spirited rough sketch, to a perfect outline. It is not CUYP, or PAUL POTTER, or SNYDERS, or TENIERS, or even WILKIE, or LANDSEER, that enchains the infant eye, or enchants his fancy; but rather the windmills, and Zeal-anders, the ships, and the horses, of a penny broadside.
