A knife could only be used with advantage when a snowbridge gives way. It is easy enough to hold a man who has fallen into a crevasse; but it is often impossible to pull him out. The whole situation is altered on a rock face. If a man falls, a sudden jerk may pull the rest of the party off the face of the mountain. This will almost certainly happen if the leader or, on a descent, the last man down, falls, unless the rope is anchored round a knob of rock, in which case--provided the rope does not break--the leader may escape with a severe shaking, though a clear fall of more than fifteen feet will usually break the rope if anchored; and, if not anchored, the party will be dragged off their holds one by one. Therefore, the leader must not fall. If any other member of the party falls, he should be held by the man above. On difficult ground, only one man moves at a time. No man moves until the man above has secured himself in a position where he can draw in the rope as the man below advances. If he keeps it reasonably taut, and is well placed, he should be able to check any slip. A climber who slips and is held by the rope can immediately get new foothold and handhold. He is not in a crevasse from which exit is impossible save at the rope’s end. His slip is checked, and he is swung up against a rock face. There is no need to drag him up. The rest of the party have passed over this face, and therefore handholds and footholds can be found. The man who has slipped will find fresh purchase, and begin again. In the case of the Matterhorn accident, the angle of the slope was about forty degrees. There was an abundance of hold, and if the rope had not parted Croz and Hadow would have been abruptly checked, and would have immediately secured themselves. Now, if Taugwalder had cut the rope, as suggested, he must have been little short of an expert acrobat, and have cut it in about the space of a second and a half _before the jerk_. If he had waited for the jerk, either he would have been dragged off, in which case his knife would have come in handy, or he would have held, in which case it would have been unnecessary.