hue, and liable, under certain circumstances, to disappear altogether; and that, therefore, whenever we have to paint such shadows, it is not only the hue of the water itself that we have to consider, but all the circumstances by which in the position attributed to them such shaded spaces could be affected. $11. Effect of Fourth If water be rippled, the side of every ripple next to us reflects a piece of the sky, and the side of every ripple farthest from us reflects a piece of the opposite shore, or of whatever objects may be beyond the ripple. But as we soon ripple on distant lose sight of the farther sides of the ripples on the retiring surface, the whole rippled space will then be reflective of the sky only. Thus, where calm distant water receives reflections of high shores, every extent of rippled surface appears as a bright line interrupting that reflection with the color of the sky. water. Fifth When a ripple or swell is seen at such an angle as to afford a view of its farther side, it carries the reflection of objects farther down than calm water would. Therefore all motion in water elongates reflections, and throws $12. Elongation of reflections by them into confused vertical lines. The real amount moving water. of this elongation is not distinctly visible, except in the case of very bright objects, and especially of lights, as of the sun, moon, or lamps by a river shore, whose reflections are hardly ever seen as circles or points, which of course they are on perfectly calm water, but as long streams of tremulous light. But it is strange that while we are constantly in the habit of seeing the reflection of the sun, which ought to be a mere circle, elongated into a stream of light extending from the horizon to the shore, the elongation of the reflection of a sail or other object to one-half of this extent is received, if represented in a picture, with incredulity by the greater number of spectators. In one of Turner's Venices the image of the white lateen-sails of the principal boat is about twice as long as the sails themselves. I have heard the truth of this simple effect disputed over and over again by intelligent persons, and yet on any water so exposed as the lagoons of Venice, the periods are few and short when there is so little motion as that the reflection of sails a mile off shall not affect the swell within six feet of the spectator. There is, however, a strange arbitrariness about this elonga tion of reflection, which prevents it from being truly felt. If we see on an extent of lightly swelling water surface the image of a bank of white clouds, with masses of higher accumulation at intervals, the water will not usually reflect the whole bank in an elongated form, but it will commonly take the eminent parts, and reflect them in long straight columns of defined breadth, and miss the intermediate lower parts altogether; and even in doing this it will be capricious, for it will take one eminence, and miss another, with no apparent reason; and often when the sky is covered with white clouds, some of those clouds will cast long tower-like reflections, and others none, so arbitrarily that the spectator is often puzzled to find out which are the accepted and which the refused. In many cases of this kind it will be found rather that the eye is, from want of use and care, insensible to the reflection than that the reflection is not there; and a little thought and careful observation will show us that what we commonly suppose to be a surface of uniform color is, indeed, affected more or less by an infinite variety of hues, prolonged, like the sun image, from a great distance, and that our apprehension of its lustre, purity, and even of its surface, is in no small degree dependent on our feeling of these multitudinous hues, which the continual motion of that surface prevents us from analyzing or understanding for what they are. Sixth Rippled water, of which we can see the farther side of the waves, will reflect a perpendicular line clearly, a bit of its length being given on the side of each wave, and easily joined § 13. Effect of by the eye. But if the line slope, its reflection will rippled water on be excessively confused and disjointed; and if horiinclined images. zontal, nearly invisible. It was this circumstance which prevented the red and white stripe of the ships at Venice, noticed above, from being visible. horizontal Seventh Every reflection is the image in reverse of just so much of the objects beside the water, as we could see if we were placed as much under the level of the water as we are actually above it. If an object be so far back from the $14. To what extent, reflection bank, that if we were five feet under the water level we could not see it over the bank, then, standing five feet above the water, we shall not be able to see its im is visible from above. age under the reflected bank. Hence the reflection of all objects that have any slope back from the water is shortened, and at last disappears as we rise above it. Lakes seen from a great height appear like plates of metal set in the landscape, reflecting the sky but none of their shores. Eighth Any given point of the object above the water is reflected, if reflected at all, at some spot in a vertical line beneath it, so long as the plane of the water is horizontal. On rippled §15. Deflection of images on agitated water. water a slight deflection sometimes takes place, and the image of a vertical tower will slope a little away from the wind, owing to the casting of the image on the sloping sides of the ripples. On the sloping sides of large waves the deflection is in proportion to the slope. For rough practice, after the slope of the wave is determined, let the artist turn his paper until it becomes horizontal, and then paint the reflections of any object upon it as on level water, and he will be right. well as of science. taken by great men. Such are the most common and general optical laws which are to be taken into consideration in the painting of water. Yet, in the application of them, as tests of good or bad water paintAn ar§ 16. Necessity of ing, we must be cautious in the extreme. watchfulness as tist may know all these laws, and comply with them, Licenses, how and yet paint water execrably; and he may be ignorant of every one of them, and, in their turn, and in certain places, violate every one of them, and yet paint water gloriously. Thousands of exquisite effects take place in nature, utterly inexplicable, and which can be believed only while they are seen; the combinations and applications of the above laws are so varied and complicated that no knowledge or labor could, if applied analytically, keep pace with them. Constant and eager watchfulness, and portfolios filled with actual statements of water-effect, drawn on the spot and on the instant, are worth more to the painter than the most extended optical knowledge; without these all his knowledge will end in a pedantic falsehood. With these it does not matter how gross or how daring here and there may be his violations of this or that law; his very transgressions will be admirable. It may be said, that this is a dangerous principle to advance in these days of idleness. I cannot help it; it is true, and must be affirmed. Of all contemptible criticism, the most to be contemned is that which punishes great works of art when they fight without armor, and refuses to feel or acknowledge the great spiritual refracted sun of their truth, because it has risen at a false angle, and burst upon them before its appointed time. And yet, on the other hand, let it be observed that it is not feeling, nor fancy, nor imagination, so called, that I have put before science, but watchfulness, experience, affection and trust in nature; and farther let it be observed, that there is a difference between the license taken by one man and another, which makes one license admirable, and the other punishable; and that this difference is of a kind sufficiently discernible by every earnest person, though it is not so explicable as that we can beforehand say where and when, or even to whom, the license is to be forgiven. In the Paradise of Tintoret, in the Academy of Venice, the Angel is seen in the distance driving Adam and Eve out of the garden. Not, for Tintoret, the leading to the gate with consolation or counsel; his strange ardor of conception is seen here as everywhere. Full speed they fly, the angel and the human creatures; the angel wrapt in an orb of light floats on, stooped forward in his fierce flight, and does not touch the ground; the chastised creatures rush before him in abandoned terror. All this might have been invented by another, though in other hands it would assuredly have been offensive; but one circumstance which completes the story could have been thought of or dared by none but Tintoret. The Angel casts a SHADOW before him towards Adam and Eve. Now that a globe of light should cast a shadow is a license, as far as mere optical matters are concerned, of the most audacious kind. But how beautiful is the circumstance in its application here, showing that the angel, who is light to all else around him, is darkness to those whom he is commissioned to banish forever. I have before noticed the license of Rubens in making his horizon an oblique line. His object is to carry the eye to a given point in the distance. The road winds to it, the clouds fly at it, the trees nod to it, a flock of sheep scamper towards it, a carter points his whip at it, his horses pull for it, the figures push for it, and the horizon slopes to it. If the horizon had been horizontal, it would have embarrassed everything and everybody. In Turner's Pas de Calais there is a buoy poised on the ridge of a near wave. It casts its reflection vertically down the flank of the wave, which slopes steeply. I cannot tell whether this is a license or a mistake; I suspect the latter, for the same thing occurs not unfrequently in Turner's seas; but I am almost certain that it would have been done wilfully in this case, even had the mistake been pointed out, for the vertical line is necessary to the picture, and the eye is so little accustomed to catch the real bearing of the reflections on the slopes of waves that it does not feel the fault. § 17. Various li censes or errors of Clande, Cuyp, in water painting Vandevelde. In one of the smaller rooms of the Uffizii at Florence, off the Tribune, there are two so-called Claudes; one a pretty wooded landscape, I think a copy, the other a marine with architecture, very sweet and genuine. The sun is setting at the side of the picture, it casts a long stream of light upon the water. This stream of light is oblique, and comes from the horizon, where it is under the sun, to a point near the centre of the picture. If this had been done as a license, it would be an instance of most absurd and unjustifiable license, as the fault is detected by the eye in a moment, and there is no occasion nor excuse for it. But I imagine it to be an instance rather of the harm of imperfect science. Taking his impression instinctively from nature; Claude usually did what is right and put his reflection vertically under the sun; probably, however, he had read in some treatise on optics that every point in this reflection was in a vertical plane between the sun and spectator; or he might have noticed walking on the shore that the reflection came straight from the sun to his feet, and intending to indicate the position of the spectator, drew in his next picture the reflection sloping to the supposed point, the error being excusable enough, and plausible enough to have been lately revived and systematized.* * Parsey's "Convergence of Perpendiculars.” I have not space here to enter into any lengthy exposure of this mistake, but reasoning is fortunately unnecessary, the appeal to experiment being easy. Every picture is the representation, as before stated, of a vertical plate of glass, with what might be seen through it, drawn on its surface. Let a vertical plate of |