Old Oran, situated fifteen leagues down stream on the same left bank of the river, is almost abandoned for the new settlement, whose population consists of Indians belonging to the Mayoruna and Orejone tribes.

Nothing can be more picturesque than this village with its ruddy-colored banks, its unfinished church, its cottages, whose chimneys are hidden amid the palms, and its two or three ubas half-stranded on the shore.
During the whole of the 7th of June the jangada continued to follow the left bank of the river, passing several unknown tributaries of no importance.

For a moment there was a chance of her grounding on the easterly shore of the island of Sinicure; but the pilot, well served by the crew, warded off the danger and remained in the flow of the stream.
In the evening they arrived alongside a narrow island, called Napo Island, from the name of the river which here comes in from the north-northwest, and mingles its waters with those of the Amazon through a mouth about eight hundred yards across, after having watered the territories of the Coto and Orejone Indians.
It was on the morning of the 7th of June that the jangada was abreast the little island of Mango, which causes the Napo to split into two streams before falling into the Amazon.
Several years later a French traveler, Paul Marcoy, went out to examine the color of the waters of this tributary, which has been graphically compared to the cloudy greenish opal of absinthe.

At the same time he corrected some of the measurements of La Condamine.

But then the mouth of the Napo was sensibly increased by the floods and it was with a good deal of rapidity that its current, coming from the eastern slopes of Cotopaxi, hurried fiercely to mingle itself with the tawny waters of the Amazon.
A few Indians had wandered to the mouth of this river.