The Archives maintain both a rare book collection and a contemporary book collection of the history of science and technology associated with Caltech.
All books are cataloged in the Caltech Library catalog, and records are also uploaded to OCLC's WorldCat database.
The rare book collection is especially notable for its core holdings in the classics of the Scientific Revolution, with first editions of Copernicus, Tycho Brahe, Galileo, Kepler, and Newton. To these masterpieces are added historic works on astronomy, mathematics, optics, magnetism, dynamics, natural history, and most recently, early works on earthquakes and engineering. Highpoints include original editions of Copernicus' De Revolutionibus Orbium Caelestium (1543); Newton's Principia mathematica in both Latin and English; the exceptionally rare third Latin edition of the same work; and original editions of the Opticks. Among other important scientific authors represented are Christian Huygens, Otto von Guericke, Robert Boyle, Robert Hooke, William Gilbert, and Simon Stevin.