Three blocks of rock detached from one of the mountains by the earthquake which produced this mighty fissure, have so fallen as to balance each other and form a natural arch, to which access is obtained by a path along the precipice. In the centre of this bridge there is an opening through which the traveller may gaze down into the infinite depth of the abyss, at the bottom of which rolls the torrent, its terrible roar mingled with the incessant screaming of thousands of birds. Sixty feet above this bridge is a second, fifty feet long by forty wide, and not more than eight feet thick in the middle. To serve as a parapet, the natives have made a slender balustrade of reeds along the edges of this second bridge, from which the traveller can obtain a fine view of the magnificent scene beneath him.
The heavy rain and bad roads made the journey to Quito very exhausting, but for all that Humboldt and Bonpland only halted there for an absolutely necessary rest, quickly pressing on for the Magdalena valley, and the magnificent forests clothing the sides of the Trinidiu in the Central Andes.
This mountain is considered one of the most difficult to cross in the whole chain. Even when the weather is favourable, twelve days, at least, are necessary for traversing the forests, in which not a human creature is seen and no food can be obtained. The highest point is 1200 feet above the sea-level, and the path leading up to it is in many parts only one foot wide. The traveller is generally carried, bound to a chair in a sitting posture, on the back of a native, as a porter carries a trunk.
"We preferred to go on foot," says Humboldt in a letter to his brother, "and the weather being very fine we were only seventeen days in these solitudes, where not a trace is to be seen of any inhabitant. The night is passed in temporary huts made of the leaves of the heliconia, brought on purpose. On the western slopes of the Andes marshes have to be crossed, into which one sinks up to the knees; and the weather having changed when we reached them, it rained in torrents for the last few days. Our boots rotted on our feet, and we reached Carthago with naked and bleeding feet, but enriched with a fine collection of new plants.
"From Carthago we went to Popayan by way of Buga, crossing the fine Cauca valley, and skirting along the mountain of Choca, with the platina-mines for which it is famous.
"We spent October, 1801, at Popayan, whence we made excursions to the basaltic mountains of Julusuito and the craters of the Puracé volcano, which discharge hydro-sulphuric steam and porphyritic granite with a terrible noise....
"The greatest difficulties were met with in going from Popayan to Quito. We had to pass the Pasto Paramos, and that in the rainy season, which had now set in. A 'paramo' in the Andes is a district some 1700 or 2000 fathoms high, where vegetation ceases, and the cold is piercing.
"We went from Popayan to Almager and thence to Pasto, at the foot of a terrible volcano, by way of the fearful precipices forming the ascent to the summit of the Cordillera, thus avoiding the heat of the Patia valley, where one night will often bring on the fever known as the Calentura de Patia, lasting three or four months."
The province of Pasto consists entirely of a frozen plateau almost too lofty for any vegetation to thrive on it, surrounded by volcanoes and sulphur-mines from which spiral columns of smoke are perpetually issuing. The inhabitants have no food but batatas, and when they run short they are obliged to live upon a little tree called "achupalla," for which they have to contend with the bear of the Andes. After being wet through night and day for two months, and being all but drowned in a sudden flood, accompanied by an earthquake near the town of Jbarra, Humboldt and Bonpland arrived on the 6th January, 1801, at Quito, where they were received in cordial and princely style by the Marquis of Selva-Alegre.
Quito is a fine town, but the intense cold and the barren mountains surrounding it make it a gloomy place to stay in. Since the great earthquake of the 4th February, 1797, the temperature has considerably decreased, and Bouguer, who registered it at an average of from 15° to 16° would be surprised to find it varying from 4° to 10° Reaumur. Cotopaxi and Pinchincha, Antisana and Illinaza, the various craters of one subterranean fire, were all examined by the travellers, a fortnight being devoted to each.