Their endeavor was to reach the missions on the Brazilian frontier, where they hoped to find a ship and the escort.

The voyage at first was favorable; it was made down the tributaries of the Amazon in a canoe.

The difficulties, however, gradually increased with the dangers and fatigues of a country decimated by the smallpox.

Of several guides who offered their services, the most part disappeared after a few days; one of them, the last who remained faithful to the travelers, was drowned in the Bobonasa, in endeavoring to help the French doctor.

At length the canoe, damaged by rocks and floating trees, became useless.
It was therefore necessary to get on shore, and there at the edge of the impenetrable forest they built a few huts of foliage.