Fables of Infidelity and Facts of Faith. Robert Patterson
for such inconvenience, some of them, as the common fly, have several hundred. But, unless our heads were as large as sugar hogsheads, we could not be so furnished, and we must either have movable eyes or see only in one direction. Accordingly, the Contriver of the eye has hung it with a hinge. Now there are various kinds of hinges, moving in one direction, and the Maker of the eye might have made a hinge on which the eye would move up and down, or he might have given us a hinge that would bend right and left, in which case we should have been able merely to squint a little in two directions. But to enable one to see in every direction, there is only one kind of hinge that would answer the purpose—the ball and socket joint—and the Former of the eye has hung it with such a hinge, retaining it in its place partly by the projection of the bones of the face, and partly by the muscles and the optic nerve, which is about as thick as a candlewick, and as tough as leather. Most of you have seen a ship, and know the way the yards are moved, and turned, and squared by ropes and pulleys. The rigging of the eye, though not so large, is fully as curious. There is a tackle, called a muscle, to pull it down when you want to look down; another tackle to pull it up when you have done; one to pull it to the right, and another to the left; there is one fastened to the eyeball in two places, and geared through a pulley which will make it move in any direction, as when we roll our eyes; and the sixth, fastened to the under side of the eye, keeps it steady when we do not need to move it. Then the eyelids are each provided with appropriate gearing, and need to have it durable too, for it is used thirty thousand times a day; in fact every time we wink. If God had neglected to place these little cords to pull up the eyelash, we should all have been in the condition of the unfortunate gentleman described by Dr. Nieuwentyt, who was obliged to pull up his eyelashes with his fingers whenever he wanted to see. There is, too, another admirable piece of forethought and skill displayed by the Former of the eye, in providing a liquid to wash it, and a sponge to wipe it with, and a waste pipe, through the bone of the nose, to carry off the tears which have been used in washing and moistening the eye. Now what absurdity to say that a law of nature, say gravity, or electricity, or magnetism has such knowledge of the principles of mechanics as the eye proclaims its Former to have—that it could make a choice among multitudes of shapes of eyes and kinds of joints, and this choice the very best for our convenience; and that having known and chosen, it could have manufactured the various parts of this complicated machine. Such a machine requires an intelligent manufacturer; and yet we have only as yet been looking at the dead eye, paying no regard to sight at all. Even a blind man's eye prove an intelligent Creator.
Let us now turn our thoughts to the instrument of sight. The optic nerve is the part of the eye which conveys visions to the mind. Suppose, instead of being where you observe it, at the back part of the eye, it had been brought out to the front, and that reflections from objects had fallen directly upon it. It is obvious that it would have been exposed to injury from every floating particle of dust, and you would always have felt such a sensation as is caused by a burn or scald when the skin peels off, and leaves the ends of the nerves exposed to the air. The tender points of the fibers of the optic nerve, too, would soon become blunted and broken, and the eye, of course, useless. How, then, is the nerve to be protected, and yet the sight not obstructed? If it were covered with skin, as the other nerves are, you could not see through it. For thousands of years after men had eyes and used them, they knew no substance, at once hard and transparent, which could answer the double purpose of protection and vision. And to this day they know none hard enough for protection, clear enough for vision, and elastic enough to resume its form after a blow. But men did the best they could, and put a round piece of brittle but transparent glass in a ring of tougher metal for the protection of the hands of a watch; and he who first invented the watch crystal thought he had made a discovery. Now, observe in the eye, that forward part is the watch glass; the cornea, made of a substance at once hard, transparent and elastic—which man has never been able to imitate—set into the sclerotica, that white, muscular coat which constitutes the white of your eye, acts as a frame for the cornea, and answers another important purpose, as we shall presently see.
But, supposing the end of the nerve protected by the glass, we might have had it brought up to the glass without any interposing lenses or humors, as, in fact, is nearly the case with some crustacea. We can not well imagine all the inconveniences of such an eye to us. If we could see distinctly at all, we could not see much farther or wider than the breadth of the end of the nerve at once. Our sight would then be very like that faculty of perceiving colors by the points of the fingers, which some persons are said to possess. In that case, seeing would only be a nicer kind of groping, and our eyes would be more conveniently fixed on the points of our fingers; or, as with many insects, on the ends of long antennae. Such a form of eye is precisely suited to the wants of an animal which has not an idea beyond its food, which has no business with any object too large for its mouth, and whose great concern is to stick to a rock and catch whatever animalculæ the water floats within the grasp of its feelers. But for a being whose intercourse should be with all the works of God, and whose chief end in such intercourse should be to behold the Creator reflected in his works, it was manifestly necessary to have a wider and larger range of vision; and, therefore, a different form of eye. Both these objects, breadth of field combined with length of range, are obtained by placing the optic nerve at the back of the eye, and interposing several lenses, through which objects are observed. By this arrangement a visual angle is secured, and all objects lying within it are distinctly visible at the same time. This faculty of perceiving several objects at the same time is a special property of sight which tends greatly to enlarge our conceptions of the knowledge of Him who gave it. A man who never saw can have no idea of it. He can not taste two separate tastes at once, nor smell two distinct smells at once; nor feel more than one object with each hand at once; and if he hears several sounds at the same time, they either flow into each other, making a harmony, or confuse him with their discord. Yet we are all conscious that we see a vast variety of distinct and separate objects at one glance of our eyes. I think it is manifest that the Former of such an eye not only intended its owner to observe such a vast variety of objects, but from the capacity of his own sight to infer the vastly wider range of vision of Him who gave it.
Besides the breadth of the field of vision, we also require length of range for the purpose of life. The thousand inconveniences which the short-sighted man so painfully feels are obvious to all. Yet it may tend to reconcile such to their lot to know that thousands of the liveliest and merriest of God's creatures can not see an inch before them. Small birds and insects, which feed on very minute insects, need eyes like microscopes to find them; while the eagle and the fish hawk, which soar up till they are almost out of sight, can distinctly see the hare or the herring a mile below them, and so must have eyes like telescopes. We, too, need to observe minute objects very closely, as when we read fine print, or when a lady threads a fine needle at microscope range; but, if confined to that range, we could not see our friends across the room, or find our way to the next street. Again, in traveling we need to see objects miles away, and at night we see the stars millions of miles away; but then, if confined to the long range, we should be strangers at home, and never get within a mile of any acquaintance. Now, how to combine these two powers, of seeing near objects and distant ones with the same eye, is the problem which the Maker of the eye had to solve. Let us look how man tried to solve it. A magnifying lens will collect the rays from any distant object, and convey them to a point called the focus. Then suppose we put this glass in the tube of an opera-glass, or pocket spy-glass, and look through the eye-hole and the concave lens, properly adjusted, in front of it, we shall see the image of the object considerably magnified. But suppose the object draws very near, we see nothing distinctly; for the rays reflected from it, which were nearly parallel while it was at a distance, are no longer so when it comes near, but scatter in all directions, and those which fall on the lens are collected at a point much nearer to the lens than before, and the eye-glass must be pushed forward to that focus. Accordingly, you know that the spy-glass is made to slide back and forward, and the telescope has a screw to lengthen or shorten the tube according to the distance of the objects observed. Another way of meeting the case would be by taking out the lens, and putting in one of less magnifying power, a flatter lens, for the nearer object. Now, at first sight, it would seem a very inconvenient thing to have eyes drawing out and in several inches like spy-glasses, and still more inconvenient