Darwin Senior relented (score one to the wizards). Excited beyond measure, Charles hurriedly wrote another letter to the Navy, this time accepting. But then he heard from FitzRoy, who told him that the post was no longer vacant. The captain had given it to a friend.
However, Darwin was top of the list if his friend changed his mind.
Darwin went to London, to make contingency plans in case he got lucky, and to keep an appointment with FitzRoy. He arrived to be told that the captain's friend had changed his mind, not five minutes earlier. (Wizards again?) His wife had objected to the length of the voyage, then planned to be three years. Did Darwin still want the job?
Lost for words, Charles nodded.
Darwin's heart sank when he saw the ship. The Beagle was a rotting, eleven-year-old brig, with ten guns. It was being rebuilt, partly at FitzRoy's own expense, so it would be seaworthy enough. But the ship was cramped, a mere 90 feet (30m) long by 24 feet (8m) wide. Could his companionship with the captain survive such a lengthy voyage in such close contact? Fortunately, he was allocated one of the larger cabins.
The Beagle's assignment was to survey the southern end of South America, in particular the complicated islands around Tierra del Fuego. The Admiralty had provided 11 chronometers for navigation, because the trip would be the first attempt to circumnavigate the Globe using marine chronometers to find longitude. FitzRoy borrowed five more, then bought six himself. So the Beagle sailed with a massive 22 chronometers on board.
The voyage started badly. Darwin was sick as a dog, crossing the Bay of Biscay, and had to endure the sound of sailors being flogged as he lay nauseated in his hammock. FitzRoy was hot on discipline, especially at the beginning of a voyage. Privately, the captain expected his `companion' to jump ship the moment it touched land, and hotfoot it back to England. The ship was supposed to put in at Madeira to take on fresh food, which would be the perfect opportunity. But the Madeira landing was cancelled because the sea was too heavy and there was no pressing need (score 3 to the wizards?).
Instead, the Beagle headed for Tenerife in the Canaries. If Charles jumped ship there, he could see the volcanoes and the Great Dragon Tree. But the consul in Santa Cruz was scared that visitors from England might introduce cholera to his islands, and he refused the Beagle permission to put into port without undergoing quarantine (score 4? We'll see). Unwilling to wait off land for the required two weeks, FitzRoy ordered the Beagle south, to the Cape Verde Islands.
It may not have been the wizards at work, but something was determined that Charles should stay on the Beagle. And now, a fifth coincidence, involving his great love, geology, made it impossible for him to do anything else. As the Beagle sailed westward, the ocean grew calm, the air warm. Darwin could trawl for plankton and jellyfish with home-made gauze nets. Things were looking up. And when they finally touched land, the island of St Jago in the Cape Verde Islands, Darwin found it hard to believe his luck. St Jago was a rugged volcanic outcrop, with conical volcanoes and lush valleys. Charles could do geology. And natural history.
He collected everything. He noticed that an octopus can change colour, and mistakenly thought this was a new discovery. After two days, he had worked out the geological history of the island, using the principles he had learned from Lyell. Lava had flowed over the seabed, trapping shells and other debris, and had later been raised to the surface. All of this must have happened relatively recently, because the shells were just like the fresh ones lying on the beach. This was not the conventional theory of the day, which held that volcanic structures were incredibly old.
The young man was coming into his own.
In the end, the voyage lasted five years, and in the whole of that time, poor Darwin never found his sea-legs. Even on the final run home, he was still seasick. But he contrived to spend most of the voyage on land, and only 18 months at sea. And while on land, he made discovery after discovery. He found fifteen new species of flatworm in Brazil. He studied rheas, giant flightless birds related to the ostrich, in Argentina. There, too, he found fossils, including the head of a giant armadillo-like glyptodont. In Tierra del Fuego he turned anthropologist, and studied the people. `I shall never forget how savage & wild one group was,' he wrote, on encountering `naked savages'. He found more fossils, among them bones of the groundsloth Megatherium and the llama-like Macrauchenia. In Chile, he studied the geology of the Andes and decided that they, and the plains beyond, had been thrust skyward in some gigantic geological upheaval.
From the South American mainland, the Beagle went north-west to the Galapagos, a tight group of a dozen or so islands, far out into the Pacific ocean. The islands had fascinating geology, mainly volcanic, and a great variety of animals that were not found anywhere else. There were the spectacular giant tortoises that had given the islands their name. Darwin measured the circumference of one as seven feet (2m). There were iguanas, and birds - boobies, warblers, finches. The finches had beaks of different shapes and sizes, depending on the food they ate, and Darwin divided them up into a series of subfamilies. He did not notice that different types of animals occurred on different islands, until Nicholas Lawson pointed this out. (The wizards again? Oh yes, this will have happened soon ...) But he did notice that the mockingbirds of Charles and Chatham islands (now Santa Maria and San Cristobal) were different species, and when, now alerted, he looked on James Island (San Salvador), he found yet a third species. But Darwin was not greatly interested in small variations in species, or how those variations corresponded to the local geography. He was vaguely aware of some theorising about species change, or `transmutation', if only from his grandfather Erasmus, but the topic didn't interest him and he saw no reason to collect evidence for or, against it.
And so the Beagle continued to Tahiti, New Zealand, and Australia.
Darwin had seen wonders that would shortly revolutionise the world. But he did not yet understand what he had seen.
In Tahiti, though, he glimpsed his first coral reef. Before leaving Australia, he was determined to find out how coral islands came into being. Lyell had suggested that because the coral animals live only in shallow waters, with ample sunlight, the reefs must be built on top of submerged volcanoes. This also explained their ringed shape. Darwin didn't believe Lyell's theory. `The idea of a lagoon island, 30 miles in diameter being based on a submarine crater of equal dimensions, has always appeared to me to be a monstrous hypothesis.' Instead, he had his own theory. He already knew that land could rise, he'd seen that in the Andes. He reasoned that if some land went up, then other land ought to go down, to maintain the balance of the Earth's crust. Suppose that when the reef started to form, the water was shallow, but then the ocean floor started descending slowly, while the coral polyps at the surface continued building the reef. Then eventually you would get a huge mountain of coral rising from what was now the ocean depths - all built by tiny creatures, always in shallow water while the building was going on. The shape? That was the result of an island with a fringing reef collapsing. The island would sink, leaving a hole in the middle, but the reef would continue to grow.