In the small poop cabin he shared with two other crew members his hammock
was strung above the table where the ship’s officers updated their sea charts, so there
was no room for privacy. On a small shelf next to his hammock were Darwin’s most
precious possessions, a copy of the Personal Narrative of a Journey to the Equinoctial
Regions of the New Continent by Alexander von Humboldt and the Principles of
Geology by Charles Lyell. It was Humboldt who reasoned that a glimpse into God’s
divine plan could be achieved by the comparison of one botanical region with another
and the English translation of his work excited Darwin to emulate his scientist hero
as he wrote:
My admiration of his famous personal narrative (part of which I almost know by heart)
determined me to travel in distant countries, and led me to volunteer as a naturalist in her
Majesty’s ship Beagle.Humboldt believed that the naturalist’s task was to discover both the diversity
and the underlying unity of nature and ‘the naturalist should aim to collect, classify,
measure and map the whole natural order’. Darwin had been so excited by Humboldt’s
description of the island of Tenerife that he had planned to organize an expedition
there himself, but the Beagle and its crew had to leave the tropical paradise without
landing because of cholera related quarantine restrictions.
One the great ironies in the history of science is that before they left England it
was Robert FitzRoy who gave Darwin a copy of the first volume of Charles Lyell’s
Principles of Geology, which had only just been published. Darwin arranged for the
remaining volumes to be sent to him and received the second volume when he was
in Montevideo. These books taught Darwin how to understand the earth in the same
language as it is currently written in, that is by understanding current landforms and
current geological processes such as erosion, deposition of sediments, glaciation
and volcanism. Lyell claimed that from his studies of the fossil record the earth
was millions of years in the making, rather than the six thousand years claimed by
theologians. (It was in 1650 that the Archbishop James Ussher calculated that the
Creation as described in the Book of Genesis had occurred on 22 October 4004 BC
and was completed six days later.)
Lyell wrote that rather than the earth being shaped by cataclysmic events such
as the biblical Flood, it was the natural processes of erosion by rain, wind and
waves followed by sedimentation and then uplift, repeated over many millions of
years, which had shaped the earth’s surface and his book was subtitled An Attempt
to Explain the Former Changes of the Earth’s Surface, by Reference to Causes Now
in Operation. However, Lyell did not extend his theories from the world of rocks
Charles Darwin – The Voyage of the Beagle 67