Disembarking from HMS Beagle on the lengthy inland expeditions that would prove so crucial for his subsequent evolutionary theorizing, Charles Darwin was conscious of the need to travel light. In the cramped quarters onboard, he had access to the ship’s “immense stock” of books, “upwards of 400 volumes!” that were ingeniously “stowed away in dry and secure places” in the poop cabin where Darwin worked and slept, and which included his own much-prized personal copies of Charles Lyell’s Principles of Geology (1830–33) and Alexander von Humboldt’s Personal Narrative of Travels to the Equinoctial Regions of the New Continent (1814–29). When on dry land among the immense vistas of South America, though, Darwin had to confine himself to just one book, and even then he was contravening Robert Fitzroy’s strict directive, “Books are never on any account to be taken out of the Vessel.” With the Beagle’s “complete library in miniature” comprising almost “all travels, & many natural history books,” Darwin’s choice of a travel reading was notable (Darwin 1985–, 1:553–54). As he recalled four decades later, “in my excursions during the voyage of the Beagle, when I could take only a single small volume, I always chose Milton.”

Paradise Lost (1667), which Darwin (2002, 48) observed was “my chief favourite,” was one of only three works of imaginative literature known to have been on board the Beagle, the others being Samuel Richardson’s sentimental epistolary novel The History of Sir Charles Grandison (1753) and Harriet Martineau’s didactic short stories Poor Laws and Paupers Illustrated (1833–34) (Darwin 1985–, 1:562–63, “Books on the Beagle”). In comparison, the shelves of the Beagle’s poop cabin groaned under the weight of more than one hundred titles on travel, geology, and natural history.