"No time," writes Professor Tyndall, "was allowed for the break's action; for I had held it firmly thus for a few seconds only, when I came into collision with some obstacle and was rudely tossed through the air, Jenni at the same time being shot down upon me. Both of us here lost our batons. We had been carried over a crevasse, had hit its lower edge, and, instead of dropping into it, were pitched by our great velocity beyond it. I was quite bewildered for a moment, but immediately righted myself, and could see the men in front of me, half-buried in the snow, and jolted from side to side by the ruts among which we were passing." Presently a second crevasse was reached. Jenni knew that it was there, and did a brave thing. He deliberately threw himself into the chasm, thinking that the strain thus put upon the rope would stop the motion. But, though he was over a hundred and eighty pounds in weight, he was violently jerked out of the fissure, and almost squeezed to death by the pressure of the rope. And so they continued to slide on. Below them was a long slope, leading directly downwards to a brow where the glacier fell precipitously; and at the base of the declivity the ice was cut by a series of profound chasms, where they must fall, and where the tail of the avalanche would cover them up forever. The three foremost men rode upon the forehead of the avalanche, and were at times almost wholly hidden by the snow; but behind, the sliding layer was not so thick, and Jenni strove with desperate energy to arrest his progress. "Halt! Herr Jesus! halt!" he shouted, as again and again he drove his heels into the firmer surface underneath. [Illustration: THE MATTERHORN.] And now let Professor Tyndall tell the rest: