<, p>This informative reference series is designed to help students understand the impact that science has had on the course of human history. Each set (the 18th and 20th century sets will come out in 2001 and 2002) focuses on a particular time period and consists of five topically arranged chapters covering life sciences, mathematics, medicine, physical sciences and technology. Chapters include a topic-specific chronology, a brief overview essay, 10-12 essays on the theories, inventions and major concepts discovered during the period, 10-12 biographies of pioneering scientists, lists of additional resources, and more. Additional features include approximately 60 black-and-white illustrations per volume, sidebars highlighting words to know and activity ideas, and general and subject indexes.