kind of zone, so lightly supported however, that the slightest touch sets them in motion. This naturally alarmed the Indians, who declined going any farther; but by persuasions and promises they succeeded in getting them to advance. Seeing, however, that the road was becoming rather worse, all further means of persuasion to induce them to proceed began to fail. They endeavored to ascend through a gulley which they had perceived on their left; but the way thither was very difficult, and was rendered more perilous by clouds which prevented their distinguishing any thing. Here the Indians entirely refused to stir any further, and having given them part of the provisions, they were sent with the baggage to wait at the place where they had encamped the night before. This circumstance very much discouraged the travellers. Being left without instruments they had to relinquish the physical and astronomical observations which they had proposed to make, and thereby missed the principal object of their journey. They nevertheless determined to persevere, for the purpose of examining well the situation, and noting such points as might facilitate any subsequent attempt undertaken with better preparations.
Soon after this the clouds dispersed, and they reached a passage which was very steep and covered with loose stones, and through which they ascended with much labor, extending their line so as to prevent the stones rolling on those below. The fatigue and the pain in their knees, obliged them to rest every eight or ten paces. After an hour's travelling in this manner they reached a body of basaltic rock, which being very steep they could not surmount but with great difficulty, and only by leaping from one rock to the other, at great risk. After this they got into a bed of loose sand, (apparently pumice stone reduced to dust,) and ascended to a very high rock, which from Mexico appears like a speck. The rock is a great mass of compact black basalt forming some imperfect pillars, the fissures being filled with solid ice.
They observed from time to time small stones falling upon them, as if thrown from above, and began to experience headache and nausea, which affected Quintana more than the others. The barometrical observation here showed an elevation of 16,895 English feet above the ocean. After taking some slight refreshments, and resting about an hour, they continued their ascent.
It is impossible to detail the particulars of the frequent difficulties and risks encountered until the explorers reached the sandy acclivity which forms the dome of the mountain, and the firmness with which they overcame them. At this point they took another
