Voyage of HMS Beagle (1831-1836): Darwin Sails the World

The second voyage of HMS Beagle was a Royal Navy survey expedition that sailed from Plymouth on 27 December 1831 and returned to Falmouth on 2 October 1836, circling the globe. On board as naturalist was the 22-year-old Charles Darwin, whose observations of fossils, geology, islands and wildlife during the voyage set him on the path to the theory of evolution by natural selection.

Background: a survey ship and a gentleman naturalist

HMS Beagle was a small ten-gun brig, launched at Woolwich in 1820 and refitted as a survey vessel. Its first voyage, to Patagonia and Tierra del Fuego in 1826–1830, ended with its captain’s suicide; command passed to the young Robert FitzRoy, an aristocratic officer with a strong interest in science. For the second voyage the Admiralty instructed FitzRoy to complete the charts of the coasts of South America and to carry a chain of chronometer measurements around the world to fix longitudes.

FitzRoy wanted an educated companion who could also collect natural history specimens. The Cambridge botanist John Stevens Henslow recommended his former student Charles Darwin, a doctor’s son who had abandoned medicine at Edinburgh and recently taken a degree at Cambridge with a view to becoming a clergyman. Darwin’s father objected to the plan, but his uncle Josiah Wedgwood II persuaded him to agree. Darwin paid his own way.

About 70 men and boys sailed in the ship, which was roughly 90 feet (27 m) long. Darwin shared a cramped chart room and suffered badly from seasickness throughout the voyage.

The route: South America

After a stop at the Cape Verde Islands in January 1832, where Darwin first studied volcanic rock, the Beagle reached Brazil. For the next three and a half years it worked along the coasts of South America while Darwin made long journeys inland.

At Punta Alta near Bahía Blanca, Argentina, in 1832 he dug up fossil bones of giant extinct mammals, including ground sloths. In Tierra del Fuego the ship returned three Fuegians whom FitzRoy had taken to England on his first voyage. Darwin rode across the pampas, visited the Falkland Islands, and crossed the Andes in 1835, finding fossil seashells high in the mountains.

On 20 February 1835 he experienced a major earthquake at Valdivia in Chile and saw its aftermath at Concepción, where the land had risen by several feet. Such observations supported the ideas of the geologist Charles Lyell, whose “Principles of Geology” Darwin read on the voyage: that the Earth’s surface had been shaped gradually by forces still at work.

The Galapagos Islands

The Beagle reached the Galapagos Islands, about 600 miles (1,000 km) off the coast of Ecuador, on 15 September 1835 and left on 20 October. Darwin went ashore on four islands, now called San Cristóbal, Floreana, Isabela and Santiago.

He noticed that the mockingbirds differed from island to island, and the islands’ vice-governor, Nicholas Lawson, told him that local people could tell which island a giant tortoise came from by its shell. Darwin collected finches but did not carefully label which island each came from, not realising their importance at the time.

Across the Pacific and home

From the Galapagos the ship crossed the Pacific to Tahiti and New Zealand, then visited Sydney and Hobart in early 1836. At the Cocos (Keeling) Islands in the Indian Ocean in April 1836, Darwin studied coral atolls and developed his theory that they form as reefs grow upward around slowly sinking volcanic islands, an idea later broadly confirmed by deep drilling.

The Beagle then called at Mauritius and Cape Town, where Darwin met the astronomer John Herschel, before crossing to St Helena and Ascension. FitzRoy returned to Bahia in Brazil to check his longitude measurements, and the ship finally reached Falmouth on 2 October 1836.

From observations to a theory

The voyage did not give Darwin an instant revelation. Its importance became clear only as experts examined his collections. In early 1837 the ornithologist John Gould reported that Darwin’s Galapagos finches were a group of closely related but distinct species, and that the mockingbirds from different islands were separate species too. Fossils studied by Richard Owen showed that extinct South American mammals were related to living ones in the same region.

In July 1837 Darwin opened a private notebook on the “transmutation of species”, and in September 1838, after reading Thomas Malthus’s essay on population, he arrived at the idea of natural selection. He developed it for two decades before the joint presentation with Alfred Russel Wallace in 1858 and the publication of On the Origin of Species in 1859.

Myths and facts

Myth: Darwin was the ship’s official naturalist. The ship’s surgeon, Robert McCormick, initially regarded himself as its naturalist and left the voyage in 1832. Darwin sailed as an unpaid gentleman companion who became the de facto naturalist.

Myth: the finches gave Darwin a “eureka” moment. The finches were a later illustration rather than a trigger. The mockingbirds, the tortoises and Gould’s analysis after the voyage mattered more to his early thinking.

Key people

Charles Darwin (1809–1882) was 22 when the voyage began. He collected thousands of specimens, kept a detailed diary and wrote long letters home, many of which Henslow read to scientific audiences in Cambridge and London, so that Darwin returned to England with a growing reputation.

Robert FitzRoy (1805–1865) was only 26 when the Beagle sailed. A skilled surveyor and a devout Christian, he later served as Governor of New Zealand and in 1854 founded the government department that became the Met Office, pioneering published weather forecasts. He came to oppose Darwin’s theory.

John Stevens Henslow (1796–1861), professor of botany at Cambridge, secured Darwin’s place and handled his specimens in England. John Gould (1804–1881), the leading bird expert of his day, and the anatomist Richard Owen described Darwin’s birds and fossils after the voyage.

Conrad Martens (1801–1878), an artist who joined the ship in 1833, painted many scenes of the voyage before settling in Sydney.

Publications and legacy

Darwin’s account of the voyage appeared in 1839 as the third volume of FitzRoy’s official narrative and was soon issued on its own; a revised edition of 1845 is the basis of the familiar “The Voyage of the Beagle”. He also edited the multi-volume “Zoology of the Voyage of HMS Beagle” and wrote books on coral reefs and volcanic islands that established him as a respected geologist.

The Beagle itself made a third survey voyage, to Australia, where a harbour was named Port Darwin after its former naturalist; the city of Darwin later grew there. The ship ended its days as a coastguard watch vessel in Essex and was sold for scrap in 1870. Today the Galapagos Islands, a national park and World Heritage Site, are closely associated with Darwin’s name.

Timeline

• 1831, 27 December: HMS Beagle sails from Plymouth.
• 1832, January: First landfall at Santiago in the Cape Verde Islands.
• 1832, September: Darwin finds giant fossil mammals at Punta Alta, Argentina.
• 1835, 20 February: Darwin experiences an earthquake at Valdivia, Chile.
• 1835, 15 September – 20 October: The Beagle surveys the Galapagos Islands.
• 1836, April: Darwin studies coral atolls at the Cocos (Keeling) Islands.
• 1836, 2 October: The Beagle reaches Falmouth, England.
• 1839: Darwin’s journal of the voyage is published.

Why it matters

The Beagle voyage turned a young would-be clergyman into one of the most important scientists in history. The specimens and observations Darwin gathered on five continents became the foundation of the theory of evolution by natural selection, while FitzRoy’s charts served sailors for generations.