Unusual Rock
Unsound rock is counterchecked by an intensification of sound method. To unusual rock we retort by an extension of our usual method. It would exaggerate its importance to discuss its varieties in greater detail than has seemed sufficient in the case of normal rock. A few instances will serve to show that our principles remain, for all rock, unaltered.
Slate has an insidious surface. The exposed edges, or spillikins, of strata may always break under a pull, unless they have allowed us to grasp a sufficiency of thickness. But slate has a worse trick. In chimney climbing, if we are using the usually safe and gentle hold of a thrust with the flat foot, or a press or push hold with the hand, against even a wide, smooth surface, the upper skin may crack locally at an uncertain distance from the point of pressure and allow foot or hand to shoot into space; and this always, unless the thrust is applied exactly at right angles to the lie of the strata. Our only safeguard is to extend to push and press holds on slate our practice with pull holds in general, and keep the direction of the pressure constant through all our lifting movement.
Quartz ledges and bands, which are the grateful solutions of many of our cliff problems, are treacherous. Quartz brittles off, in crystals or in masses, in unexpected directions. We cannot test it adequately until our full weight comes upon it; when it may be too late. And so we never step on to projecting quartz, or scale the vertical face of a seam, unless we have hand or foot hold upon good rock above or below it. Happily, quartz seams are usually narrow. We prefer soft-soled shoes, which will distribute the pressure over the uneven facets. Boot-nails snap the projecting crystals or slide on the flat facets, especially after rain. The fingers similarly must take general holds, and not trust to salient prisms. The direction of the growth of the crystals can guide us in applying our pressures. A seam lying back at a steep angle sometimes leaves good rock holds along its edges, where quartz and rock have weathered at an unequal rate. A seam at a gentle angle as often provides a delightful traverse of escape.
Soft sandstone, which in quarries and elsewhere is frequently used as a practice ground, has its own fashion of soft crumbling and its own body of hardened adherents. Its outlines are recognizable, and in mountain masses we avoid it altogether. But those who attempt it locally must remember that it is peculiarly deceptive for footwork. Its ledges dissolve under a stiff boot. Sand shoes, or still better, boots, are the only wear. Beginners should look for lines of ascent where the subjacent heaps are still uncarted and propitious in the event of failure. Old sandstone, when it emerges, is firmer for the feet but offers little handhold, and makes very fatiguing climbing.
Chalk, and the methods of dealing with it, form a study by themselves. Chalk climbing provides the missing link between rock and ice technique. Those who frequent its cliffs use big claws and ice methods, and pronounce it to be an unrivalled training for ice work. Its occasional hard surface and its abundant projecting flints, whose security is in inverse ratio to their graspability, have to be treated with the measures of precaution proper to unsound rock.
Marble builds peaks of imposing outline, but its edges are not constructed with an eye to good foot climbing. Its surfaces, where exposed, slope against us; its slipperiness dictates the use of soft soles; while the rubble with which it is cumbered makes soft soles comfortless. It has appeared to me more often dangerous than difficult.
Old lava is as tiresome as quartz, and less often available as a last resource. Desperately hard for the feet, it yet snaps out in diamond cubes and litters with wrenching rubble its already jarring surface. I know of no sound climbs upon it.
Gritstone has its own devotees and a growing literature. Its climbs and their mosaic perils have all the charm of a well-executed miniature.
Limestone, as the layman uses the term, is deceitful, and offers ridiculously little good climbing in proportion to the amount of it that protrudes plausibly from the surface of Europe. One of the closest escapes I have experienced was from a spontaneous fall of limestone rock on a venerable and bland-looking western cliff. In the form of ‘dolomite’ it offers very agreeable sharp-edged dwarf-climbs even in our islands, and it is to be regretted we have so little of good stature.