We have also to make sure of the lie of the strata, not only for convenience of hold, but also because on the side towards which the stratification dips the moisture fallen on the mountain will drain, and we shall have to look out for our principal enemies—wet rock, rock corrupted by moisture, and, in winter, an icing or glaze.
Our islands provide us with a great variety of rock structure and hill forms, and, according as we get to know the aspects of one hill of any local type, it is interesting to reconstruct the unseen aspects of its neighbours. Several good climbing cliffs were first found in this way.
The look of the outline will suggest the sort of climbing we shall find on the faces. We get further information from the nature and size of any scree slopes below a cliff. The presence or absence of verdure, and the sight of the belts, knots and surface minutiæ, tell us the rest.
All the local rock of the same aspect and in the same structural line will be similar, and may be bad; but if we can get at another aspect of it, on an opposite hillside, it may be of good holding character. For which reason rickety ridgelets may be faced across the valley by sober and admirable slabs.
Mist and cloud in Britain are our frequent companions. Mist may do us good service by throwing an unsuspected ridge or pinnacle into relief. But as a rule the alterations which cloud and fog effect in mountain details falsify rather than reveal. Their use is to place a greater value upon the fidelity with which previous reconnoitring has been conducted, and its result remembered, if we wish, in mist, to arrive at an intended climb at all, or to make descent into the right valley on our return. Not impossibly they are sent by nature to complicate what is otherwise the over-easy mountaineering training of our hills; to handicap the specializing gymnast, and to enforce the practices of observing detail, using the compass and map, and exercising judgment, memory, and the precious sense of direction.
The Half-seen
In the Alps or unfamiliar regions, to discover the truth about what may be termed the half-seen,—that is, about formation or detail which should be visible but for foreshortening, distance, angle or light,—new snow is again our best auxiliary. Its presence suggests, even emphasizes, much that is unsuspected. Seemingly straight ridges are shown to be crooked, and plain faces rough. It helps us with light in hidden corners, and annihilates distance.
Otherwise we have to use days of driving cloud, or wait for the morning or evening moments of thin mist, when the drift lies across the face or through the ridge, and picks out its angles, features and perspective. Mists will often reveal the existence of ridges and pinnacles, whose separation from the face behind is undiscoverable as seen in front or in clear light.
Of more frequent service are the hours when the sunlight falls across the face from the side, and the protuberances and hollows jump into stereoscopic clearness in shadow and the modifications of light. Invisible snow depressions, bosses and foreshortened angles of rock slab or ledge are cheerfully betrayed by the veracity of cross-shadows; and points and lines of obstinate sunlight, which remain salient and surprising after the sun has deserted all the rest of the seemingly even surface of snow or rock, proclaim to us unexpected inequalities and therefore possibilities of passage.
In cases of outside difficulty upon rock, where we are reconnoitring some great rock wall, of a granite or dolomitic type, we can generally make sure of the vertical rifts and clefts from below; but the presence or size of transverse fractures or belts is hidden from us. In this case assurance as to what has been only half-seen can be completed if a downward view of the rock, or of its local type, is also obtainable. The information is best secured from the summit of the peak itself, reached by another route, and many great first ascents have owed their discovery and safe accomplishment to such complementary inspection. Only a short section need be in sight from above in order to indicate the general character of the cross belts, and the last section on such peaks is always the more important to examine, as it will generally be the severest in its details. But even without this local visitation a downward or oblique view of any section of the face, or of an allied or neighbouring wall of similar structure, will give adequate information, and convert the half-seen into the two-thirds made certain.