receive very few rays, and the water looks black. In looking along water we receive reflected rays, and therefore the image of objects above it. Hence, in shallow water on a level shore the bottom is seen at our feet, clearly; it becomes more and more obscure as it retires, even though the water do not increase in depth, and at a distance of twelve or twenty yards-more or less according to our height above the water—becomes entirely invisible, lost in the lustre of the reflected surface.

modifies dark re

not affect bright

oncs.

Second: The brighter the objects reflected, the larger the angle at which reflection is visible; it is always to be remembered that, strictly speaking, only light objects are reflected, and that the darker ones are seen only in proportion to $7. The inherent hue of water the number of rays of light that they can send ; so flections, and does that a dark object comparatively loses its power to affect the surface of water, and the water in the space of a dark reflection is seen partially with the image of the object, and partially transparent. It will be found on observation that under a bank-suppose with dark trees above showing spaces of bright sky, the bright sky is reflected distinctly, and the bottom of the water is in those spaces not seen; but in the dark spaces of reflection we see the bottom of the water, and the color of that bottom and of the water itself mingles with and modifies that of the color of the trees casting the dark reflection.

This is one of the most beautiful circumstances connected with water surface, for by these means a variety of color and a grace and evanescence are introduced in the reflection otherwise impossible. Of course at great distances even the darkest objects cast distinct images, and the hue of the water cannot be seen, but in near water the occurrence of its own color modifying the dark reflections, while it leaves light ones unaffected, is of infinite value.

Take, by way of example, an extract from my own diary at Venice.

"May 17th, 4 P. M. Looking east the water is calm, and reflects the sky and vessels, with this peculiarity; the sky, which is pale blue, is in its reflection of the same kind of blue, only a little deeper; but the vessels' hulls, which are black, are reflected in pale sea green, i.e., the natural color of the water under sunlight; while the orange masts of the vessels, wet with a recent

shower, are reflected without change of color, only not quite so bright as above. One ship has a white, another a red stripe," (I ought to have said horizontal along the gunwales,) of these the water takes no notice.'

"What is curious, a boat passes across with white and dark figures, the water reflects the dark ones in green, and misses out all the white; this is chiefly owing to the dark images being opposed to the bright reflected sky."

I have left the passage about the white and red stripe, because it will be useful to us presently; all that I wish to insist upon here is the showing of the local color (pea green) of the water in the spaces which were occupied by dark reflections, and the unaltered color of the bright ones.

Third: Clear water takes no shadow, and that for two reasons; A perfect surface of speculum metal takes no shadow, (this the reader may instantly demonstrate for himself,) and a $8. Water takes perfectly transparent body as air takes no shadow; hence water, whether transparent or reflective,

no shadow.

takes no shadow.

:

But shadows, or the forms of them, appear on water frequently and sharply it is necessary carefully to explain the causes of these, as they are one of the most eminent sources of error in water painting. First Water in shade is much more reflective than water in sunlight. Under sunlight the local color of the water is commonly vigorous and active, and forcibly affects, as we have seen, all the dark reflections, commonly diminishing their depth. Under shade, the reflective power is in a high degree increased,* and it will be found most frequently that the forms of shadows are expressed on the surface of water, not by actual shade, but by more genuine reflection of objects above. This is another most important and valuable circumstance, and we owe to it some phenomena of the highest beauty.

A very muddy river, as the Arno for instance at Florence, is seen during sunshine of its own yellow color, rendering all reflections discolored and feeble. At twilight it recovers its

* I state this merely as a fact: I am unable satisfactorily to account for it on optical principles, and were it otherwise, the investigation would be of little interest to the general reader, and little value to the artist.

reflective power to the fullest extent, and the mountains of Carrara are seen reflected in it as clearly as if it were a crystalline lake. The Mediterranean, whose determined blue yields to hardly any modifying color in daytime, receives at evening the image of its rocky shores. On our own seas, seeming shadows are seen constantly cast in purple and blue, upon pale green. These are no shadows, but the pure reflection of dark or blue sky above, seen in the shadowed space, refused by the local color of the sea in the sunlighted spaces, and turned more or less purple by the opposition of the vivid green.

$9. Modification

We have seen, however, above, that the local color of water, while it comparatively refuses dark reflections, accepts bright ones without deadening them. Hence when a shadow is thrown across a space of water of strong local color, reof dark reflections ceiving, alternately, light and dark reflections, it has no power of increasing the reflectiveness of the water in the bright spaces, still less of diminishing it; hence, on all the dark reflections it is seen more or less distinctly, on all the light ones it vanishes altogether.

by shadow.

Let us take an instance of the exquisite complexity of effect induced by these various circumstances in co-operation.

Suppose a space of clear water showing the bottom under a group of trees, showing sky through their branches, casting shadows on the surface of the water, which we will suppose also to possess some color of its own. Close to us, we shall see the bottom, with the shadows of the trees clearly thrown upon it, and the color of the water seen in its genuineness by transmitted light. Farther off, the bottom will be gradually lost sight of, but it will be seen in the dark reflections much farther than in the light ones. At last it ceases to affect even the former, and the pure surface effect takes place. The blue bright sky is reflected truly, but the dark trees are reflected imperfectly, and the color of the water is seen instead. Where the shadow falls on these dark reflections a darkness is seen plainly, which is found to be composed of the pure clear reflection of the dark trees; when it crosses the reflection of the sky, the shadow of course, being thus fictitious, vanishes.

Farther, of course on whatever dust and other foulness may be present in water, real shadow falls clear and dark in propor

tion to the quantity of solid substance present. On very muddy rivers, real shadow falls in sunlight nearly as sharply as on land; on our own sea, the apparent shadow caused by increased reflection, is much increased in depth by the chalkiness and impurity of the water.

Farther, when surface is rippled, every ripple, up to a certain variable distance on each side of the spectator, and at a certain angle between him and the sun, varying with the size and shape of the ripples, reflects to him a small image of the sun. Hence those dazzling fields of expanding light so often seen upon the

sea.

Any object that comes between the sun and these ripples, takes from them the power of reflecting the sun, and in consequence, all their light; hence any intervening objects cast apparent shadows upon such spaces of intense force, and of the exact shape, and in the exact place of real shadows, and yet which are no more real shadows than the withdrawal of an image of a piece of white paper from a mirror is a shadow on the mirror. Farther, in all shallow water, more or less in proportion to its shallowness, but in some measure, I suppose, up to depths of forty or fifty fathoms, and perhaps more, the local color of the water depends in great measure on light reflected from the bottom. This, however, is especially manifest in clear rivers like the Rhone, where the absence of the light reflected from below forms an apparent shadow, often visibly detached some distance from the floating object which casts it.

10. Examples on

Rhone.

The following extract from my own diary at the water of the Geneva, with the subsequent one, which is a continuation of that already given in part at Venice, will illustrate both this and the other points we have been stating.

"GENEVA, 21st April, Morning.

"The sunlight falls from the cypresses of Rousseau's island straight towards the bridge. The shadows of the bridge and of the trees fall on the water in leaden purple, opposed to its general hue of aquamarine green. This green color is caused by the light being reflected from the bottom, though the bottom is not seen; as is evident by its becoming paler towards the middle of

the river, where the water shoals, on which pale part the purple shadow of the small bridge falls most forcibly, which shadow, however, is still only apparent, being the absence of this reflected light, associated with the increased reflective power of the water, which in those spaces reflects blue sky above. A boat swings in the shoal water; its reflection is cast in a transparent pea-green, which is considerably darker than the pale aquamarine of the surface at the spot. Its shadow is detached from it just about half the depth of the reflection; which, therefore, forms a bright green light between the keel of the boat and its shadow; where the shadow cuts the reflection, the reflection is darkest and something like the true color of the boat; where the shadow falls out of the reflection, it is of a leaden purple, pale. The boat is at an angle of about 20° below. Another boat nearer, in deeper water, shows no shadow, whatsoever, and the reflection is marked by its transparent green, while the surrounding water takes a lightish blue reflection from the sky."

The above notes, after what has been said, require no comment; but one more case must be stated belonging to rough water. Every large wave of the sea is in ordinary circumstances divided into, or rather covered by, innumerable smaller waves, each of which, in all probability, from some of its edges or surfaces reflects the sunbeams; and hence result a glitter, polish, and vigorous light over the whole flank of the wave, which are, of course, instantly withdrawn within the space of a cast shadow, whose form, therefore, though it does not affect the great body or ground of the water in the least, is sufficiently traceable by the withdrawal of the high lights; also every string and wreath of foam above or within the wave takes real shadow, and thus adds to the impression.

I have not stated one-half of the circumstances which produce or influence effects of shadow on water; but lest I should confuse or weary the reader, I leave him to pursue the subject for himself; enough having been stated to establish this general principle, that whenever shadow is seen on clear water, and, in a measure, even on foul water, it is not, as on land, a dark shade subduing where it falls the sunny general hue to a lower tone; but it is a space of an entirely different color, subject itself, by its susceptibility of reflection, to infinite varieties of depth and