Hero of Alexandria invented the aeolipile, a primitive steam engine, in the first century. A hollow sphere with elbow-shaped tubes mounted on an axle and suspended over a cauldron of boiling water, the engine likely could not have powered anything. “It should probably be remembered,” wrote historian William Rosen, “as the first in a line of engineering dead ends.”

A scholar in Peking contracted malaria in 1899 and was given medication with an ingredient labeled “dragon bones.” The bone chips, he found, were inscribed with writing dating back to China’s second dynasty. Thousands more were uncovered in the decades following; many of these “oracle bones” had inscriptions recording celestial events, which scientists have since used to calculate changes in the length of an earth day and in the rate of the earth’s rotation.

Members inducted into the U.S. National Inventors Hall of Fame in 2010 included Yvonne Brill, whose electrothermal hydrazine thruster keeps satellites in space orbit, as well as Arthur Fry and Steven Silver, who created sticky notes (Fry, the concept; Silver, the glue). “Note: It took one woman to invent a rocket thruster,” wrote a Washington Post reporter about the induction ceremony, “and two men to invent Post-its.”

Archaeologists in France discovered in 1865 a Stone Age human skull with a hole sawed in it. They believed it had served as a drinking vessel; one wrote the hole was “expressly made for the application of the lips.” But later study by an anatomist proved this to be incorrect: the skull was actually evidence of ancient brain surgery.