Mapping the Spectrum is a major contribution to the growing body of studies on science as practice, mainly because of its emphasis on visual representation. Joseph Wahelder, Ambix well researched and profusely illustrated book. Joseph Wahelder, Ambix The beautiful illustrations are a visual pleasure ... Mapping the Spectrum is a must for historians of science. In addition, it can be great fun for scientists who are interested in the sunny side of their field, before the computer transformed it to such an extent that its origins are almost unrecognizable. Angewandte Chemie [Hentschel] surveys and orders his topic with the same diligence and scrutiny that 19th-century spectroscopists employed in their field. Angewandte Chemie ... a fascinating and satisfying book ... incorporating some 140 illustrations, copious footnotes and a leisurely, multi-threaded analysis dominated by abundant historical examples ... The book makes valuable reading both for its analytical perspectives and for the historical tapestry of individuals and techniques that it interrelates. British Journal for the History of Science Physicists, chemists and astronomers, as well as historians and philosophers of science and ideas, and the intelligent layman will all find much that is thought provoking and fascinating in this book, which also includes an extensive bibliography.