Sec. 33. No happy chance--nay, no happy thought--no perfect knowledge--will ever take the place of that mighty unconsciousness. I have often had to repeat that Turner, in the ordinary sense of the words, neither knew nor thought so much as other men. Whenever his _perception_ failed--that is to say, with respect to scientific truths which produce no results palpable to the eye--he fell into the frankest errors. For instance, in such a thing as the relation of position between a rainbow and the sun, there is not any definitely visible connection between them; it needs attention and calculation to discover that the centre of the rainbow is the shadow of the spectator's head.[79] And attention or calculation of this abstract kind Turner appears to have been utterly incapable of; but if he drew a piece of drapery, in which every line of the folds has a _visible_ relation to the points of suspension, not a merely calculable one, this relation he will see to the last thread; and thus he traces the order of the mountain crests to their last stone, not because he knows anything of geology, but because he instinctively seizes the last and finest traces of any visible law. [Illustration: FIG. 72.] Sec. 34. He was, however, especially obedient to these laws of the crests, because he heartily loved them. We saw in the early part of this chapter how the crest outlines harmonized with nearly every other beautiful form of natural objects, especially in the continuity of their external curves. This continuity was so grateful to Turner's heart that he would often go great lengths to serve it. For instance, in one of his drawings of the town of Lucerne he has first outlined the Mont Pilate in pencil, with a central peak, as indicated by the dotted line in Fig. 72. This is nearly true to the local fact; but being inconsistent with the general look of crests, and contrary to Turner's instincts, he strikes off the refractory summit, and, leaving his pencil outline still in the sky, touches with color only the contour shown by the continuous line in the figure, thus treating it just as we saw Titian did the great Alp of the Tyrol. He probably, however, would not have done this with so important a feature of the scene as the Mont Pilate, had not the continuous line been absolutely necessary to his composition, in order to oppose the peaked towers of the town, which were his principal subject; the form of the Pilate being seen only as a rosy shadow in the far off sky. We cannot, however, yet estimate the importance, in his mind, of this continuity of descending curve, until we come to the examination of the lower hill _flanks_, hitherto having been concerned only with their rocky summits; and before we leave those summits, or rather the harder rocks which compose them, there is yet another condition of those rocks to be examined; and that the condition which is commonly the most interesting, namely, the Precipice. To this inquiry, however, we had