is the first history of the evolution of cosmic dimensions, from the work of Eratosthenes and Aristarchus in the third century B.C. to the efforts of Edmond Halley (1656—1742). "Van Helden's authoritative treatment is concise and informative; he refers to numerous sources of information, draws on the discoveries of modern scholarship, and presents the first book-length treatment of this exceedingly important branch of science."—Edward Harrison, "Van Helden writes well, with a flair for clear explanation. I warmly recommend this book."—Colin A. Ronan,