Portland printer David Wolfe’s lecture, “Letterpress: The Conduit of Knowledge,” was an eagerly anticipated part of this rainy weekend. Unfortunately, while Wolfe is apparently a fine printer, he is not the most riveting public speaker. Disappointed, I sought to claim more value from my admission ticket by walking the floor of the Boston Antiquarian Book Fair.

There was a wealth of very old stuff—a mix of nicely ornamented but inaccurate maps and beautiful leather-bound volumes—from sellers as near as New England and as distant as the UK, the Netherlands, and Germany. How about a 1713 edition of Isaac Newton’s Philosophiæ Naturalis Principia Mathematica? The binding is in “like new” condition! I’ve seen old books before, but the book fair differs from museums and libraries in a number of ways. One can hold and browse pretty much anything. Many sellers will talk endlessly in praise of a piece, offering interesting historical context. And if beautiful print is not enough for you, many titles bear inscriptions penned by famous hands.

Something about the handwritten inscription captivates me. I saw the signatures of Marie Curie and Charles Lindbergh. Sir Ernest Shackleton dedicated his massive tome, The Heart of the Antarctic , to someone long forgotten. Ah, the age of discovery and exploration! Franklin D. Roosevelt awarded one copy of Moby Dick to a kid who won a school contest. (That book is now worth $2500.) John F. Kennedy wrote an indecipherably messy gift message for a copy of Profiles in Courage on a White House business card. “Joe Heller” dedicated an early copy of Catch-22 to a “fellow airman.”

There was plenty of ephemera. Some were very reasonably priced, like a program from the funeral of William Henry Harrison (not autographed). Others were more extravagant, like an 1860 copy of Base Ball Player’s Pocket Companion ($20,000).

One bookseller had a copy of Claude Shannon‘s 1937 master’s thesis—the one which demonstrates for the first time that Boolean algebra, and therefore computers, could solve any numerical problem. There was also a copy of the Bell System Technical Journal in which Shannon outlined some of the fundamentals of cryptography. Once it was established that we all went to MIT (I, the bookseller, and Claude Shannon), a 1904 handout appeared, documenting the details of the proposed merger between MIT and Harvard. It was marked “Confidential.”

The craziest binding clearly belonged to a book by Belgian artist Edgar Claes, whose cover is a colorful meshwork of interconnected gears.

The document that held my attention the longest was also one of the most plain. It was a simple card on stationery marked “SUPREME HEADQUARTERS, ALLIED EXPEDITIONARY FORCE.” It informed the bearer that he was about to “embark upon the Great Crusade” in Normandy. In closing, it offered: “Good Luck! And let us all beseech the blessing of Almighty God upon this great and noble undertaking.” [signed] Dwight Eisenhower

It can be yours for $6500.