Chapter 1, pt2: Tenerife

Mount Teide (known to Darwin as the Peak of Teneriffe) rising above the clouds. Photo by darksidex - flickr. Licensed under CC BY 2.0 via Wikimedia Commons. 

On the 6th of January we reached Teneriffe, but were prevented landing, by fears of our bringing the cholera: the next morning we saw the sun rise behind the rugged outline of the Grand Canary Island, and suddenly illumine the Peak of Teneriffe, whilst the lower parts were veiled in fleecy clouds. This was the first of many delightful days never to be forgotten.

After eleven days at sea, the Beagle reached Teneriffe, the largest of the Canary Islands, a Spanish-controlled archipelago stretching westward into the Atlantic from near the shores of Morocco. She had attempted to put in at Madeira a few days earlier, on the 4th, but strong winds made FitzRoy leery the prospect of approaching Madeira's sheer cliffs. Instead, the Beagle continued southward, planning to stop at Santa Cruz de Tenerife.

FitzRoy's account of the voyage gives more detail on this episode. The Beagle had just dropped anchor at Santa Cruz de Tenerife, a "sun-burned, uninviting town," when a boat from the Health Office approached and informed them they could not land without performing a strict 12-day quarantine. They had apparently heard that a cholera epidemic that was spreading through Europe at the time had reached England, and were unwilling to take chances. After weighing his options, FitzRoy chose to continue southward without further delay.

Darwin's account, written years later, describes this as "the first of many delightful days never to be forgotten." FitzRoy offers a slightly different story:

This was a great disappointment to Mr. Darwin, who had cherished a hope of visiting the Peak. To see it—to anchor and be on the point of landing, yet be obliged to turn away without the slightest prospect of beholding Teneriffe again—was indeed to him a real calamity.

The Peak of Teneriffe 

Mount Teide, or "the Peak of Teneriffe," seems to have loomed large in Darwin's imagination, if not that of every adventurer of his day. Alexander von Humboldt had climbed it in 1799, at the beginning of his famous Latin American expedition, and made many notes on its geology and botany in his seven-volume Personal Narrative (1809-1829).  Humboldt was the most famous naturalist in the world at the time of Darwin's voyage, and Darwin had read and re-read his works religiously; they were probably the reason for his desire to travel to Tenerife in the first place.

1843 portrait of Alexander von Humboldt by Joseph Karl Stieler. Licensed under Public Domain by Wikimedia Commons.

But Darwin was far from the only person who attached great symbolic significance to Mount Teide. A massive stratovolcano, rising from sea level to 12,200 feet in altitude, the mountain was visible from ships at sea over 100 miles away, signaling one of the key ports en route between Europe and South America. FitzRoy, in his narrative of the voyage, described it as the "monarch of the Atlantic."

Astronaut photo of Mount Teide. Image by NASA.

Tenerife, like the other Canary Islands, is a volcano that his risen from the sea floor over millions of years. Originally, over 5 million years ago, it was actually three islands, formed by three shield volcanoes — broad, gently sloping volcanoes that erupt fluid, basaltic lava that runs easily down their slopes. With time, a series of stratovolcanoes formed, uniting the three islands into one. Stratovolcanoes erupt more silica-rich, less fluid lava, along with blasting out ash and rock fragments, all of which combine to build a tall, steep edifice. The modern peak of Teide formed within a caldera created by the collapse of a previous stratovolcano as its eruption emptied the magma chamber underlying it.

Landsat image of Tenerife showing the rim of the caldera and the peak of Mount Teide. Image by NASA, licensed under public domain via Wikimedia Commons.