Item 78 is an example of Einstein at his most basic: Ist die Trägheit eines Körpers von seinem Energieinhalt abhängig? (Does the inertia of a body depend upon its energy-content?). This predates his really complicated general theory of relativity, but introduced the concept everyone knows, even if we don't fully understand - E=mc2. If you have trouble understanding it too, perhaps this 1905 first printing will explain it, provided you can read the original German. $6,500.

Item 45 is George Catlin's Letters and Notes on the Manners, Customs and Condition of the North American Indians. Catlin became interested in America's Indians as a young man, so in the 1830s, he headed west to draw their images, determined to capture their culture before it was permanently altered by settlement. He drew over 500 pictures, which he displayed on world tours after his return from the West. In 1841, he published this two-volume work, with over 300 illustrations. $5,700.

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