ILLUSTRATIVE NOTES.
Note 1, [p. 42].—"Principle of the stereoscope."
247. I am sorry to find a notion current among artists, that they can, in some degree, imitate in a picture the effect of the stereoscope, by confusion of lines. There are indeed one or two artifices by which, as stated in the text, an appearance of retirement or projection may be obtained, so that they partly supply the place of the stereoscopic effect, but they do not imitate that effect. The principle of the human sight is simply this:—by means of our two eyes we literally see everything from two places at once; and, by calculated combination, in the brain, of the facts of form so seen, we arrive at conclusions respecting the distance and shape of the object, which we could not otherwise have reached. But it is just as vain to hope to paint at once the two views of the object as seen from these two places, though only an inch and a half distant from each other, as it would be if they were a mile and a half distant from each other. With the right eye you see one view of a given object, relieved against one part of the distance; with the left eye you see another view of it, relieved against another part of the distance. You may paint whichever of those views you please; you cannot paint both. Hold your finger upright, between you and this page of the book, about six inches from your eyes, and three from the book; shut the right eye, and hide the words "inches from," in the second line above this, with your finger; you will then see "six" on one side of it, and "your," on the other. Now shut the left eye and open the right without moving your finger, and you will see "inches," but not "six." You may paint the finger with "inches" beyond it, or with "six" beyond it, but not with both. And this principle holds for any object and any distance. You might just as well try to paint St. Paul's at once from both ends of London Bridge as to realize any stereoscopic effect in a picture.
Note 2, [p. 59].—"Dark lines turned to the light."
248. It ought to have been farther observed, that the inclosure of the light by future shadow is by no means the only reason for the dark lines which great masters often thus introduce. It constantly happens that a local color will show its own darkness most on the light side, by projecting into and against masses of light in that direction; and then the painter will indicate this future force of the mass by his dark touch. Both the monk's head in [Fig. 11] and dog in [Fig. 20] are dark towards the light for this reason.
Note 3, [p. 98].—"Softness of reflections."
249. I have not quite insisted enough on the extreme care which is necessary in giving the tender evanescence of the edges of the reflections, when the water is in the least agitated; nor on the decision with which you may reverse the object, when the water is quite calm. Most drawing of reflections is at once confused and hard; but Nature's is at once intelligible and tender. Generally, at the edge of the water, you ought not to see where reality ceases and reflection begins; as the image loses itself you ought to keep all its subtle and varied veracities, with the most exquisite softening of its edge. Practice as much as you can from the reflections of ships in calm water, following out all the reversed rigging, and taking, if anything, more pains with the reflection than with the ship.
Note 4, [p. 100].—"Where the reflection is darkest, you will
see through the water best."
250. For this reason it often happens that if the water be shallow, and you are looking steeply down into it, the reflection of objects on the bank will consist simply of pieces of the bottom seen clearly through the water, and relieved by flashes of light, which are the reflection of the sky. Thus you may have to draw the reflected dark shape of a bush: but, inside of that shape, you must not draw the leaves of the bush, but the stones under the water; and, outside of this dark reflection, the blue or white of the sky, with no stones visible.
Note 5, [p. 101].—"Approach streams with reverence."