Collectors snap up pricey historical materials. (Physics for Sale).

Want a glimpse of Albert Einstein's mind at work? Last week, it cost a buyer $559,500.

An unprecedented sale of manuscripts, books, and reports documenting the development of modern physics took place at Christie's auction house in New York on Oct. 4. It brought in nearly $1.8 million. The highest-selling documents were those attributed to the most famous physicists, with 8 of the top 10 written by Einstein.

The half-million-dollar centerpiece of the Harvey Plotnick Library, named for the man who collected the items, was a handwritten 1913 manuscript by Einstein and his colleague Michele Besso.

Using early versions of Einstein's general theory of relativity, Einstein and Besso unsuccessfully struggled with an anomaly in Mercury's motion that's not explicable with Issac Newton's theory of gravitation. The manuscript contains more than 50 pages of calculations.

"It's a snapshot of Einstein's thinking process," says Francis Wahlgren, head of the books and manuscripts department at Christie's in New York. The Einstein-Besso document is one of only two existing works-in-progress showing how Einstein developed the general theory of relativity. The other, the Zurich Notebook, is in the Einstein Archives at Hebrew University in Jerusalem.

"I can't say that the average collector can read it and see into the mind of Einstein," says Spencer Weart, the director of the Center for History of Physics at the American Institute of Physics in College Park, Md. But whether you are a physicist or not, says Weart, "you can feel that what you're holding is a genuine representation of the creative process of what may count as the most amazing scientific discovery of all time."

One of the few pre-20th-century physicists represented in the sale was Newton, whose gravitational theory Einstein improved upon with the general theory of relativity. Newton came in second on the list of top sellers: A small scrap of manuscript added to the second English edition of his Opticks, published in 1717, sold for $89,625.

Rounding out the top three, a copy of Einstein's 1916 book on the general theory of relativity sold for $83,650. This particular volume was marked up by the Nobel laureate Wolfgang Pauli, who, as a teenager, used it to teach himself general relativity. "You see the mind of one person trying to comprehend the mind of another person," says Weart.

The entire sale, "says something about the acceptance of science as a cultural element, not just as something of practical value," adds Weart. "It points out that people see a work of science in the way they would see a great painting or a bone of an ancestor."