With high hopes, they put their craft into the water and moved down stream. But on the fourth day, they found rapids ahead. And from that time on, they were constantly obliged to land and carry their dugouts and stores round a cataract.
The peril of being swept over the falls, was always imminent, and as the trail, which constituted their portages, had to be cut through the matted forest, their labours were increased. In the first eleven days, they progressed only sixty miles. No one knew the distance they would have to traverse, nor how long the river would be broken by falls and cataracts, before it came down into the plain of the Amazon.
Some of their canoes were smashed on the rocks. Two of the natives were drowned. They watched their provisions shrink. Contrary to their expectations, the forest had almost no animals. If they could shoot a monkey or a monster lizard, they rejoiced at having a little fresh meat.
Tropical insects bit them day and night and caused inflammation and even infection. Man-eating fish lived in the river, making it dangerous for the men when they tried to cool their inflamed bodies by a swim.
Most of the party had malaria, and could be kept going only by large doses of quinine. Roosevelt, while in the water, wounded his leg on a rock; inflammation set in, and prevented him from walking, so that he had to be carried across the portages.
The physical strength of the party, sapped by sickness and fatigue, was visibly waning. Still the cataracts continued to impede their progress and to add terribly to their toil. The supply of food had shrunk so much, that the rations were restricted, and amounted to little more than enough to keep the men able to go forward slowly.
Then fever attacked Roosevelt, and they had to wait for a few days, because he was too weak to be moved. He besought them to leave him and hurry along to safety, because every day they delayed consumed their diminishing store of food, and they might all die of starvation.
They refused to leave him, however. A change for the better in his condition came soon. They moved forward. At last they left the rapids behind them, and could drift and paddle on the unobstructed river.
Roosevelt lay in the bottom of a dugout, shaded by a bit of canvas put up over his head, and too weak from sickness even to splash water on his face; for he was almost fainting from the muggy heat and the tropical sunshine.
Forty-eight days, after they began their voyage on the River of Doubt, they saw a peasant, a rubber-gatherer, the first human being they had met. Thenceforward they journeyed without incident.