||1:SCIENCE works with problems by making them into manageable, manipulable abstractions.||2:Jon Agar's ambitious new book sets out to synthesise the insights of many recent historians of science.||3:These might be anything from a field biologist's notes of lemming populations on Spitzbergen to a physicist's creation of muon tracks in a cloud chamber, or from a set of equations in the mathematical imagination to a vast computer model of the world's climate.