292

DESCENT OF BOULDERS.

hit by the falling stones, and crushed to pieces. Havingthus learned the worst, we descended to the Montanvertamid drenching rain.

On the morning of the 18th there was no cloud tobe seen anywhere, and the sunlight glistened brightly onthe surface of the ice. We ascended to the Tacul. Thespontaneous falling of the stones appeared more frequentthis morning than I had ever seen it. The sun shonewith unmitigated power upon the ice, producing copiousliquefaction. The rustle of falling debris was incessant,and at frequent intervals the boulders leaped down theprecipice, and rattled with startling energy amid the rocksat its base. I sent Simond to the top to remove the looserstones; he soon appeared, and urged the moraine-shinglein showers down the precipice, upon a bevelled slope ofwhich some blocks long continued to rest. They wereout of the reach of the guide’s baton, and he sought todislodge them by sending other stones down upon them.Some of them soon gave way, drawing a train of smallershingle after them ; others required to be hit many timesbefore they yielded, and others refused to be dislodgedat all. I then cut my way up the precipice in the manneralready described, fixed the stake, and descended asspeedily as possible. We afterwards fixed the bottomstake, and on the 20th the displacements of all three weremeasured.* The spaces passed over by the respectivestakes in 24 hours were found to be as follows:—

Inches.

Top stake ..Middle stakeBottom stake

6-00

4-50

2-56

The height of the precipice was 140'8 feet, but it slopedoff at its upper portion. The height of the middle

* On this latter occasion my guide volunteered to cut the steps for meup to the pickets; and I permitted him to do so. In fact, he was at last asanxious as myself to see the measurement carried out.