Book excerpt: A unique A-to-Z reference of brilliance in innovation and invention Combining engagingly written, well-researched history with the respected imprimatur of Scientific American magazine, this authoritative, accessible reference provides a wide-ranging overview of the inventions, technological advances, and discoveries that have transformed human society throughout our history. More than 400 entertaining entries explain the details and significance of such varied breakthroughs as the development of agriculture, the "invention" of algebra, and the birth of the computer. Special chronological sections divide the entries, providing a unique focus on the intersection of science and technology from early human history to the present. In addition, each section is supplemented by primary source sidebars, which feature excerpts from scientists' diaries, contemporary accounts of new inventions, and various "In Their Own Words" sources. Comprehensive and thoroughly readable, Scientific American Inventions and Discoveries is an indispensable resource for anyone fascinated by the history of science and technology. Topics include: aerosol spray * algebra * Archimedes' Principle * barbed wire * canned food * carburetor * circulation of blood * condom * encryption machine * fork * fuel cell * latitude * music synthesizer * positron * radar * steel * television * traffic lights * Heisenberg's uncertainty principle