The Imbabura volcano, celebrated for its destructive eruptions of mud and water, stands midway between the two ranges at the northern end of the plateau, and belongs to the transverse ridge of knot (nudo) which unites them. It is the most northern of the higher peaks of Ecuador, with the exception of Cotocachi, and possibly of Chiles on the Colombian frontier, and reaches the elevation of 15,033 ft. Ibarra on the northern flanks of the volcano has suffered severely from its eruptions. The name is derived from imba, fish, and bura, mother, and is said to have originated from the quantities of a fish called “preñadilla” (Pimelodus cyclopum) discharged from its crater during one of its eruptions—a phenomenon which, after a searching investigation, was discredited by Wagner. Cayambe, or Cayembi, the second highest peak of the Ecuadorean Andes, has the noteworthy distinction of standing very nearly on the equator. Its base covers a large area, and its square top, rising far above the snow-line, is one of the sights of Quito. Antisana is crowned with a double dome, and is described as an extinct volcano, though Humboldt saw smoke issuing from it in 1802. On its western side is the famous hacienda (farm) of Antisana, 13,306 ft. above the sea, where Humboldt resided for several months in 1802. Sara-Urcu stands south-east of Antisana in a densely forested region, drenched with rain and only slightly explored. Sincholagua and Rumiñagui are the next two peaks, going southward, and then the unrivalled cone of Cotopaxi (q.v.)—the highest active volcano in the world—from whose summit smoke curls upward unceasingly.
Llanganati or Cerro Hermoso is chiefly known through the tradition that the treasures of the Incas were buried in a lake on its slopes. It consists of a group of summits, the highest being credited with 17,843 ft. Tunguragua, or Tungurahua, has a cone-shaped summit like that of Cotopaxi, with a slope of 38°. It rises from a plain somewhat lower than the neighbouring central plateau and stands free from the surrounding elevations, except on the south, which give it an exceptionally imposing appearance. Among its characteristic features is a cataract fed by melting snows, which descends 1500 ft. in three leaps, and an enormous basaltic lava-stream, which crosses the face of the mountain in a north-easterly direction. Its most notable eruption was in 1777. It has been sometimes classed among the extinct volcanoes, but smoke has been seen issuing from it at different dates, and a violent eruption occurred on January 12, 1886. The fertile cultivated valley of Baños, with its thermal springs, lies at the base of Tunguragua, which F. Hassaurek describes as “the most beautiful of all the snow peaks in the country.” The next in line is El Altar, which the natives call Capac-Urcu (“king mountain”), whose broken cone and impressive outlines make it one of the most attractive mountains of Ecuador. Its summit comprises a group of eight snow-clad peaks, and its crater is surrounded by a steep and jagged wall of rocks. There is a tradition that this mountain was once higher than Chimborazo, but a series of eruptions caused the cone to fall in and reduced its summit to its present altitude and broken appearance. Altar has shown no signs of activity since the discovery of America. Sangay, or Sangai, the next and last large volcano to the south, is in a state of frequent eruption, however, and is known as one of the most restless volcanoes of the world. Since the Spanish conquest it has been in a state of uninterrupted activity, but no damage has been done, because there are no civilized settlements in its immediate vicinity. Though of great interest to scientific investigators because of this unceasing activity, and of its peculiar position in the Andean system, and because of the difficult and dangerous country by which it is surrounded, Sangay has been but rarely visited by European travellers. Its eruptions are not on a grand scale, but small outbursts of lava and explosions of steam occur at frequent intervals, and at longer intervals more violent explosions in which the molten rock is thrown 2000 ft. above its summit, and ashes are carried away as far as the streets of Guayaquil.
Turning to the Cordillera Occidental and taking the principal peaks in order from south to north, the first to claim attention is Chimborazo (from Chimpu-raza, “mountain of snow”), the highest summit of Ecuador, and once believed to be the culminating point of the Andes. Humboldt, who unsuccessfully attempted its ascent in 1802, gives its elevation as 21,425 ft., Reiss and Stubel as 20,703, and Whymper as 20,498. It stands 76 m. north-east of Guayaquil, and, according to Spruce, rises majestically from the valley of the Guayas, on the west, without a “positive break from the summit down to the plain.” This, however, is erroneous, for Whymper located a detached range running parallel with the Cordillera on the west, for a distance of 65 m. with the Chimbo valley between them. The magnificence of its mass is imposing from almost any point of view, but it can be most fully appreciated from its western or Pacific side, where its base is covered with forest up to the snow-line, above which its pure white cone rises another 5000 ft. An unobstructed view of the great mountain is rarely obtained, however, because of the mists and clouds which cover its cone. Its summits were reached for the first time in 1880 by Edward Whymper, all previous attempts having failed. It is considered to be an extinct volcano because it makes the plumb-line deviate only 7″ to 8″, from which it is deduced that the mountain is hollow. Moreover, the calcined matter resembling white sand which covers its sides below the snow-line, extensive beds of lava, and the issue of streams of hot water from its northern side, seem to confirm the deduction that Chimborazo is an extinct volcano. Immediately north of Chimborazo, and separated from it by only a narrow valley, are the lower triple summits of Carahuairazo, or Carguairazo (which the natives call Chimborazo-embra, “Chimborazo’s wife”), whose hollow cone collapsed in 1698 during a great earthquake, and left the jagged rim which adds so much to its present picturesque appearance. Mr Whymper’s measurement is for the middle peak. Quirotoa, still farther north, is supposed to have suffered a similar catastrophe. Its hollow summit, 13,510 ft. above sea-level, now contains a large lake. Iliniza, which stands west by north of Cotopaxi, has two pyramidal peaks, and is one of the most interesting mountains of the Ecuadorean group. It stands at the western end of the Tiupullo ridge, and overlooks the Quito basin to the north-east. The French academician Bouger, who was chief of the scientific commission sent to Ecuador in 1736 to measure a degree of the meridian on the equator, made a trigonometrical measurement of Iliniza, and Wagner ascended to within 800 ft. of its summit in 1859. The geological structure of the mountain furnishes no evidence of volcanic activity. Chamalari, which the Spaniards called El Corazon from its heart-shaped appearance, is similarly destitute of a crater. It overlooks the Quito basin and has been ascended many times. Among the earlier explorers to reach its summit were Bouger and La Condamine, Humboldt and Bonpland, and José Cáldas, the Granadian naturalist. Atacatzo is an extinct volcano, with nothing noteworthy in its appearance and history. Pichincha, its famous neighbour, is apparently of later origin, according to Wagner, and of slightly lower elevation. Perhaps no Ecuadorean volcano is better known than Pichincha, the “boiling mountain,” because of its destructive eruptions and its proximity to the city of Quito. Its summit comprises three groups of rocky peaks, of which the most westerly, Rucu-Pichincha (Old Pichincha), contains the crater, a funnel-shaped basin 2460 ft. deep and about 1500 ft. wide at the bottom, whose walls in places rise perpendicularly and in others at an angle of 20°. The exterior of the cone has an angle of 30°. Bouger and La Condamine were the first to reach its brink in 1742, after which Humboldt made the ascent in 1802, Boussingault and Hall in 1831, Garcia Moreno and Sebastian Wisse in 1844 and 1845 (descending into the crater for the first time), Garcia Moreno and Jameson in 1857, Farrand and Hassaurek in 1862, Orton in 1867, and Whymper in 1880. Farrand spent more than a week in the crater trying to get some good photographic views, and Orton has given a graphic description of his experiences in the same place. He found that the real cone of eruption was an irregular heap 250 ft. in height and 800 ft. in diameter, containing about 70 vents. The temperature of the vapour within the fumarole was 184°, and water boiled at 189°. There have been five eruptions of Pichincha since the Spanish conquest—in 1539, 1566, 1575, 1587 and 1660. The second covered Quito 3 ft. deep with ashes and stones, but the last three were considered as the most destructive to that city. The last happily broke down the western side of the crater, which, it is believed, will ensure the city against harm in any subsequent eruption. Since the earthquake of August 1867 Pichincha has sent forth dense masses of black smoke and great quantities of fine sand. Cotocachi is a double-peaked mountain, rising from an extremely rough country. It was ascended by Whymper in 1880. All the higher summits of Ecuador have true glaciers, the largest being found on Antisana, Cayambe and Chimborazo. Whymper located and named no less than eleven on Chimborazo, and counted twelve on Cayambe.
There are two distinct hydrographic systems in Ecuador—the streams that flow south-eastward to the Marañon, or Amazon, and those which flow westward to the Pacific. The southern part of the great central plateau is arid and has a very light rainfall; it has no streams, therefore, except from melting snows, and the higher elevations which receive the Rivers.impact of the easterly winds. Farther north the rainfall becomes heavier, the plateau is covered with vegetation, and a considerable number of small rivers flow westward through the Cordillera to the Pacific. The Eastern Cordillera, or Andes, forms the water-parting between the two systems. The largest of the eastward-flowing rivers is the Napo, which rises in the eastern defiles of Cotopaxi and Sincholagua—the principal source being the Rio del Valle, which traverses the Valle Vicioso. It at first flows south by east, and at the village of Napo is 1450 ft. above sea-level, at the mouth of the Coca 858 ft., at the mouth of the Aguarico 586 ft., 500 at the mouth of the Curaray, and 385 at its junction with the Marañon. Orton estimates its current at Napo in the month of November as 6 m. an hour; in the next 80 m. the river falls 350 ft. and produces a fine series of rapids; and from Santa Rosa downwards the rate is not less than 4 m. an hour. Its breadth at Napo is only 120 ft., but at Coca it has widened to 1500 ft., and at its mouth to nearly 1 m. Like most of the large Amazon tributaries, its discharge into the Marañon is through several distinct channels. The Napo is navigable for steam-boats for some distance above the mouth of the Coca, and thence for canoes as far as the Cando cataract, 3332 ft. above the sea. Its total length is 920 m. The principal tributaries of the Napo are the Coca and Aguarico from the north, and the Curaray from the south. The Coca rises on the eastern slopes of the Andes near Cayambe and the Guamani range, and flows eastward near the equator to San Rafael (about 76° 30′ W. long.), where it turns sharply southward to a junction with the Napo in about lat. 1° S., long. 76° W. The