Because they are not shown in true contrast to the sky, and to other high lights. Nature paints her shadows in pale purple, and then raises her lights of heaven and sunshine to such height that the pale purple becomes, by comparison, a vigorous dark. But poor Turner has no sun at his command to oppose his pale colors. He follows Nature submissively as far as he can; puts pale purple where she does, bright gold where she does; and then when, on the summit of the slope of light, she opens her wings and quits the earth altogether, burning into ineffable sunshine, what can he do but sit helpless, stretching his hands towards her in calm consent, as she leaves him and mocks at him! Sec. 11. "Well," but you will farther ask, "is this right or wise? ought not the contrast between the masses be given, rather than the actual hues of a few parts of them, when the others are inimitable?" Yes, if this _were_ possible, it ought to be done; but the true contrasts can NEVER be given. The whole question is simply whether you will be false at one side of the scale or at the other,--that is, whether you will lose yourself in light or in darkness. This necessity is easily expressible in numbers. Suppose the utmost light you wish to imitate is that of serene, feebly lighted, clouds in ordinary sky (not sun or stars, which it is, of course, impossible deceptively to imitate in painting by any artifice). Then, suppose the degrees of shadow between those clouds and Nature's utmost darkness accurately measured, and divided into a hundred degrees (darkness being zero). Next we measure our own scale, calling our utmost possible black, zero;[18] and we shall be able to keep parallel with Nature, perhaps up to as far as her 40 degrees; all above that being whiter than our white paper. Well, with our power of contrast between zero and 40, we have to imitate her contrasts between zero and 100. Now, if we want true contrasts, we can first set our 40 to represent her 100, our 20 for her 80, and our zero for her 60; everything below her 60 being lost in blackness. This is, with certain modifications, Rembrandt's system. Or, secondly, we can put zero for her zero, 20 for her 20, and 40 for her 40; everything above 40 being lost in _white_ness. This is, with certain modifications, Paul Veronese's system. Or, finally, we can put our zero for her zero, and our 40 for her 100; our 20 for her 50, our 30 for her 75, and our ten for her 25, proportioning the intermediate contrasts accordingly. This is, with certain modifications, Turner's system;[19] the modifications, in each case, being the adoption, to a certain extent, of either of the other systems. Thus, Turner inclines to Paul Veronese; liking, as far as possible, to get his hues perfectly true up to a certain point,--that is to say, to let his zero stand for Nature's zero, and his 10 for her 10, and his 20 for her 20, and then to expand towards the light by quick but