Mungo Park’s Second Niger Expedition — Forty men sent to trace a river; nearly all died

In 1805 the Scottish surgeon and explorer Mungo Park led a British government expedition of roughly forty Europeans inland from the Gambia to trace the course of the River Niger to its end. Within a few months almost the entire party was dead. By the time Park reached the Niger at Bamako in mid-August 1805, only eleven of the Europeans were still alive; the rest had died of malaria and dysentery on the march. By the time he built a boat and set off down the river from Sansanding on 19 November 1805, the European company had shrunk to Park himself, one army officer, three soldiers and a few others. Park drowned at the Bussa rapids, on the Niger in what is now Nigeria, in about 1806, when his boat was attacked by people on the riverbanks and the men leapt into the water to escape. None of the Europeans who entered the boat survived; only an African guide, Amadi Fatouma, lived to carry the story out.

The expedition was the second time Park had gone to the Niger. His first journey, of 1795–97, had been a privately backed reconnaissance for the African Association; he had reached the river at Ségou in July 1796, the first European known to have seen it there, and returned to write a celebrated account. That success persuaded the British government to mount the far larger venture of 1805 — a column of soldiers and artificers commissioned to follow the Niger downstream and settle the geographical question of where it went. The difference between the two journeys was fatal: the small, lightly equipped first expedition had given Park the prestige that justified the second, while the second’s size, its soldiers and its timing turned it into a death march.

The decisive error was the calendar. The party left the coast late and pushed inland into the West African rainy season, the deadliest time of year for malaria, with no understanding of how the disease was transmitted and no effective protection against it. Men sickened and died at a catastrophic rate, the column melting away stage by stage until barely a tenth of it remained. Park pressed on regardless, converting the survivors’ situation into an all-or-nothing dash down the river. The attempt ended in violence at a rapids he could not pass, and with it the lives of nearly all the men he had led inland. The expedition is remembered as one of the costliest in the history of African exploration measured against the size of the party — a venture in which the science of geography advanced barely at all, while almost everyone who set out died.

The River of Doubt — An uncharted river that nearly killed a president

The Roosevelt–Rondon Scientific Expedition descended the Rio da Dúvida — the “River of Doubt,” an uncharted tributary of the Amazon in the Brazilian state of Mato Grosso — between February and April 1914, and very nearly killed the former United States president Theodore Roosevelt. It was led jointly by Roosevelt and the Brazilian army officer and explorer Colonel Cândido Mariano da Silva Rondon, who had discovered the river’s headwaters in 1909 and whose expertise, discipline and knowledge of the interior carried the party through. Of roughly twenty-two people who descended the river, three died: one paddler drowned in rapids, one camarada was murdered by another, and the killer was left behind in the forest. Roosevelt survived, gravely weakened, and never fully recovered his health.

The expedition trekked overland across the Brazilian highlands from December 1913, reaching the put-in on the River of Doubt and beginning the descent on 27 February 1914. The river proved far worse than imagined: a succession of rapids, gorges and waterfalls that forced exhausting portages, smashed and swamped the dugout canoes, and stretched a journey planned for weeks into a two-month ordeal through fever country. The camaradas — the Brazilian backwoodsmen who paddled and hauled — bore the heaviest labour. On 15 March the paddler Antônio Simplício da Silva drowned when his canoe was lost in the rapids; his body was never recovered. In early April a camarada named Julio de Lima, caught stealing food, shot and killed the foreman Manoel Vicente da Paixão; Julio fled into the jungle and was left behind.

Roosevelt himself nearly became the fourth death. On about 22 March he badly gashed his leg helping to free a canoe, the wound became infected, and malarial fever drove his temperature toward 105°F; the expedition’s physician, Dr José Antônio Cajazeira, twice operated, once lancing an abscess. Delirious and unable to walk, Roosevelt at one point asked to be left behind so as not to slow the others, and his son Kermit refused to allow it. The party reached Rondon’s pre-arranged relief at the confluence with the Aripuanã River on about 26 April 1914. Rondon renamed the river the Rio Roosevelt. Roosevelt, who had lost a quarter of his body weight, returned home broken in health and died less than five years later.