5. _x x x_. Sinuous lines worn by the water, indicative of some softness or flaws in the rock; these probably the occasion or consequence of the formation of the great precipice or brow on the right. We shall have more to say of them in Chap. XVII. [Illustration: FIG. 71.] 6. _g f_, _g f_, &c. Broad aqueous or glacial curvatures. The sixth group in Aiguille Bouchard. 7. _k l_, _k l_. Concave curves wrought by the descending avalanche; peculiar, of course, to this spot. 8. _i h_, _i h_. Secondary convex curves, glacial or aqueous, corresponding to _g f_, but wrought into the minor secondary ravine. This secondary ravine is associated with the opponent aiguillesque masses _r s_; and the cause of the break or gap between these and the crests B D is indicated by the elbow or joint of nearer rock, M, where the distortion of the beds or change in their nature first takes place. Turner's idea of the structure of the whole mass has evidently been that in section it was as in Fig. 71, snapped asunder by elevation, with a nucleus at M, which, allowing for perspective, is precisely on the line of the chasm running in the direction of the arrow; but he gives more of the curved aiguillesque fracture to these upper crests, which are greater in elevation (and we saw, sometime ago, that the higher the rock the harder). And that nucleus of change at M, the hinge, as it were, on which all these promontories of upper crest revolve, is the first or nearest of the evaded stones, which have determined the course of streams and nod of cliffs throughout the chain.