A one-volume desk encyclopedia, with about 4,000 entries, including 1,000 capsule biographies, covering the key terms, concepts, instruments, and individuals in the development of the sciences and mathematics, from classical times to the present. The majority of the entries, ranging from a half-dozen lines to a full page in length, focus on the so-called "hard sciences", which are commonly taught in high school -- biology, chemistry, physics, earth science -- as well as mathematics through calculus. Astronomy, physical anthropology, archaeology, and technology also are covered, albeit to a lesser extent. In all cases, the entries, supplemented by some 150 line drawings, avoid technical terms, making the text easily accessible to students, teachers, librarians, journalists, and readers generally. Even professional scientists will find "The Penguin Desk Encyclopedia of Science and Mathematics" to be a useful resource for checking dates and facts outside their areas of particular expertise.