Nearly due south of Quito is the great volcanic cone of El Altar. Like all the peaks of this high plateau, El Altar rises to a great height above the sea, being at the present time 16,383 feet above the sea. This mountain has an enormous crater that appears to be dormant or extinct, and is covered with snow. According to the traditions of Indians, El Altar, or, as they call it, _Capac Urcu_ or _The Chief_, was the highest mountain near the equator, being much higher than Chimborazo. But during a prodigious eruption that occurred before the discovery of America, and continued uninterruptedly for eight years, the height of the mountain was considerably reduced. According to Boussingault, the fragments of the cone of this celebrated mountain are now spread for great distances around the mountain on the surrounding lowlands. Pichincha in Ecuador, an extinct volcano, is situated almost immediately on the equator. It has a height as measured by Whymper by the barometer, of 15,918 feet above the Pacific. The summit is covered by blocks of pumice. Several species of lichens are found at this elevation. According to Daubeny, Pichincha was extinct prior to 1539, when it became active. There were also eruptions in 1577, 1587, and 1668. It was also in activity during 1831. Cayamba, another volcanic mountain of Ecuador, lies to the east of Pichincha, a short distance north of the equator. Its height is 19,186 feet. It is nearly extinct. Cotopaxi, 19,680 feet, is another volcanic mountain of the high plateau of Quito. Cotopaxi is still active. Its slopes are covered with snow down to a height of about 14,800 feet. Between the lower edge of this snow line and the lower slopes of the mountain, there lies a zone of naked rock. According to Whymper, the eruption of Cotopaxi, in 1877, was preceded by an unusual degree of activity in the earlier parts of the year. This, however, did not cause any alarm until June 25th, 1877, when, shortly after midday, an eruption, attended by tremendous subterranean roars, began, and an immense black column shot up into the air for about twice the height of the cone. This eruption was clearly visible at Quito, for the wind blew the ashes towards the Pacific. At this time the summit had not changed its appearance, but towards 6:30 A. M., on the next day, another enormous column of ashes rose from the crater. The ashes and cinders were first carried due north by the winds, and then, spreading out in all directions, were subsequently distributed through the air all over the country. At Quito, as early as 8 A. M., the sky assumed the appearance it generally has at twilight, and the darkness increased until midday, when it became as dark as at midnight. Indeed, it was so dark that one could not see his hand before his face.