Einstein Equation-Filled Letter Sold for $71,811

A handwritten letter by Albert Einstein filled with mathematical equations examining covariance and invariance in Hamiltonian mechanics sold for $71,811 at RR Auction's latest Fine Autographs and Artifacts sale.

The undated, single-page letter was written in German to mathematician Chaim Herman Müntz with whom Einstein corresponded during the late 1920s. The document contains extensive calculations as Einstein examines how equations in classical mechanics behave under mathematical transformations. After completing his calculations, Einstein writes "We probably cannot demand more than that" before suggesting that he and Müntz use the equation to investigate what he calls "the problem of the rotator".

The letter is accompanied by its original mailing envelope, postmarked in Potsdam, Germany, apparently in 1929.

“What's interesting about this letter is that you can follow Einstein's calculations across the entire page,” said Bobby Livingston, executive vice president at RR Auction. “He's working through the mathematics, explaining his reasoning to a fellow mathematician and suggesting what they should investigate next. You can see the progression of his thinking right on the page.”

Other highlights included:

• King Edward IV signed document dispossessing a Lancastrian supporter of his estates following the Wars of the Roses (sold for $37,535)
• King Henry VIII signed document addressed to the keeper of the wardrobe ($33,901)
• King Henry VII signed documen ordering the delivery of a coat of arms ($30,718)
• autograph scrapbook featuring signatures of Babe Ruth, Lou Gehrig, Thomas Edison, Amelia Earhart, George Gershwin and Calvin Coolidge ($28,759)
• Anton Chekhov handwritten letter discussing his play The Seagull, his growing fame and a visit from Leo Tolstoy ($20,625)