On 24th August 1831, Charles Darwin’s great friend and mentor John Stevens Henslow sat down at his desk, took up his pen, and wrote what turned out to be one of the most important letters in the history of science:
My dear Darwin,
Before I enter the immediate business of this letter, let us condole together upon the loss of our inestimable friend poor Ramsay of whose death you have undoubtedly heard long before this. I will not now dwell upon this painful subject as I shall hope to see you shortly fully expecting that you will eagerly catch at the offer which is likely to be made to you of a trip to Terra del Fuego & home by the East Indies— I have been asked by Peacock who will read & forward this to you from London to recommend him a naturalist as companion to Capt Fitzroy employed by Government to survey the S. extremity of America— I have stated that I consider you to be the best qualified person I know of who is likely to undertake such a situation— I state this not on the supposition of yr being a finished Naturalist, but as amply qualified for collecting, observing, & noting any thing worthy to be noted in Natural History. Peacock has the appointment at his disposal & if he can not find a man willing to take the office, the opportunity will probably be lost— Capt F. wants a man (I understand) more as a companion than a mere collector & would not take any one however good a Naturalist who was not recommended to him likewise as a gentleman. Particulars of salary &c I know nothing. The Voyage is to last 2 yrs & if you take plenty of Books with you, any thing you please may be done— You will have ample opportunities at command— In short I suppose that there never was a finer chance for a man of zeal & spirit . Capt F. is a young man. What I wish you to do is instantly to come to Town & consult with Peacock (at No 7 Suffolk Street Pall Mall East or else at the University Club) & learn further particulars. Don’t put on any modest doubts or fears about your disqualifications for I assure you I think you are the very man they are in search of—so conceive yourself to be tapped on the Shoulder by your Bum-Bailiff [*] & affecte friendJ.S. Henslow
Darwin didn’t receive Henslow’s letter until 29th August. Many years later, toward the end of his life, he recollected:
On returning home from my short geological tour in North Wales, I found a letter from Henslow, informing me that Captain Fitz-Roy was willing to give up part of his own cabin to any young man who would volunteer to go with him without pay as naturalist to the Voyage of the ‘Beagle’. I have given, as I believe, in my MS. Journal an account of all the circumstances which then occurred; I will here only say that I was instantly eager to accept the offer, but my father strongly objected, adding the words, fortunate for me, “If you can find any man of common sense who advises you to go I will give my consent.” So I wrote that evening and refused the offer. On the next morning I went to Maer to be ready for September 1st, and, whilst out shooting, my uncle (Josiah Wedgwood.) sent for me, offering to drive me over to Shrewsbury and talk with my father, as my uncle thought it would be wise in me to accept the offer. My father always maintained that he was one of the most sensible men in the world, and he at once consented in the kindest manner. I had been rather extravagant at Cambridge, and to console my father, said, “that I should be deuced clever to spend more than my allowance whilst on board the ‘Beagle’;” but he answered with a smile, “But they tell me you are very clever.”
The rest, as they say, is history.
[*] Footnote: Being a bum-bailiff wasn’t quite as rude as it sounds: they were bailiffs notorious for following close at the heels (or, rather, bums!) of debtors.