For more than a century, a small, leather-bound book has sat collecting dust and attracting little attention in a gray stone library on the corner of Brown University’s Main Green in Providence, R.I. In a library full of old and obscure texts, the 234-page quarto was older and more obscure than most. Its brown, battered leather cover was blank, its title page missing, and its author unknown. Inside, a series of inscrutable symbols filled every inch of the book’s margins: Scrawled in black ink were what looked like a combination of Greek, Hebrew, and some wholly invented characters. Who wrote them? And what do they say?
The only hint came from an unsigned note attached to the book and dated Nov. 11, 1817. It read, in part, “The margin is filled with Short Hand Characters, Dates, Names of places &c. &c. by Roger Williams or it appears to be his hand Writing…. brot me from Widow Tweedy by Nicholas Brown Jr.”
Despite this intriguing reference to the man who founded Rhode Island and brought the idea of religious liberty to the New World, the book languished—until an offhand remark at a small lecture in 2010 led a team of Brown scholars and undergraduates to crack the code, confirm it was written in Roger Williams’ hand, and discover, this summer, his last known work of theology.
On a late fall day in 2010, Ted Widmer, then-director of Brown’s John Carter Brown Library, was giving a talk on Williams’ life and legacy to about 20 members of the Pembroke Club, a group of Brown alums. The attendees were “mostly people with either gray hair or no hair,” says Bill Twaddell, a retired diplomat and member of the library’s board of governors who sat in on the lecture.
At one point, Widmer (an occasional contributor to Slate) mentioned the book and the suspicion that Williams had authored the code in its margins. Twaddell’s ears perked up. Why not scan the code and let computers attempt to crack it?
With the help of Kim Nusco, the JCB’s manuscript librarian, Widmer and Twaddell began recruiting faculty from the fields of mathematics, computer science, comparative literature, and history. But 17th century penmanship triumphed over 21st century technology: The writing was simply too messy for a computer to make sense of.
Manually cracking the code was going to be a slog. The project didn’t neatly fall into any one field, and the academics recruited by Widmer, Twaddell, and Nusco had work of their own to worry about. They decided to give Brown’s undergrads a shot.
In the fall of 2011, two juniors and two seniors—students of history, American studies, and mathematics—signed on to tackle the code during the spring semester. But over winter break, one team member, Lucas Mason-Brown, decided to get a head start. (Full disclosure: Mason-Brown is a friend.)
Mason-Brown studied math and had a particular interest in cryptography. He began with a basic technique called frequency analysis. It relies on statistical truths—for example that e is the most common letter in the English language—to crack the kinds of simple ciphers one would expect from the Colonial era.
It yielded nothing. He then turned to co-occurrence analysis, a more sophisticated technique based on the frequency with which certain letters tend to succeed or precede others. For example, the most commonly occurring pair of letters, or bigram, in English is t and h.
Still nothing. The cipher might have been more complex than expected. Or it could combine elements of the six other languages Williams knew. If that were the case, the uselessness of frequency analysis would be the least of the group’s problems.