When I first laid out the framework for A History of Ancient Mathe matical Astronomy, I intended to carry the discussion down to the last applications of Greek astronomical methodology, i. e. Copernicus, Brahe, and Kepler. But as the work proceeded, it became evident that this plan was much too ambitious, and so I decided to terminate my History with late antiquity, well before Islam. Nevertheless, I did not discard the running commentary that I had prepared when studying De revolutionibus in its relation to the methodology of the Almagest. Only recently, E. S. Kennedy and his collaborators had opened access to the" Maragha School" (mainly Ibn ash-Shalir), revealing close parallels to Copernicus's procedures. Accordingly, it seemed useful to make available a modern analysis of De revolutionibus, and thus in 1975 I prepared for publication "Notes on Copernicus. " In the meantime, however, Noel Swerdlow, also starting from Greek astronomy, not only extended his work into a deep analysis of De revolu tionibus, but also systematically investigated its sources and predecessors (Peurbach, Regiomontanus, etc. ). I was aware of these studies through his publications as well as from numerous conversations on the subject at The Institute for Advanced Study and at Brown University. It became clear to me that my own investigations lay at too superficial a level, and I therefore withdrew my manuscript and suggested to Swerdlow that he undertake a thoroughgoing revision and amplification of my "Notes. " His acceptance of my proposal initiated the present publication."

In the second millennium b.c., Babylonian scribes assembled a vast collection of astrological omens, believed to be signs from the gods concerning the kingdom's political, military, and agricultural fortunes. The importance of these omens was such that from the eighth or seventh until the first century, the scribes observed the heavens nightly and recorded the dates and locations of ominous phenomena of the moon and planets in relation to stars and constellations. The observations were arranged in monthly reports along with notable events and prices of agricultural commodities, the object being to find correlations between phenomena in the heavens and conditions on earth. These collections of omens and observations form the first empirical science of antiquity and were the basis of the first mathematical science, astronomy. For it was discovered that planetary phenomena, although irregular and sometimes concealed by bad weather, recur in limited periods within cycles in which they are repeated on nearly the same dates and in nearly the same locations.

N. M. Swerdlow's book is a study of the collection and observation of ominous celestial phenomena and of how intervals of time, locations by zodiacal sign, and cycles in which the phenomena recur were used to reduce them to purely arithmetical computation, thereby surmounting the greatest obstacle to observation, bad weather. The work marks a striking advance in our understanding of both the origin of scientific astronomy and the astrological divination through which the kingdoms of ancient Mesopotamia were governed.

Originally published in 1998.

The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

In the second millennium b.c., Babylonian scribes assembled a vast collection of astrological omens, believed to be signs from the gods concerning the kingdom's political, military, and agricultural fortunes. The importance of these omens was such that from the eighth or seventh until the first century, the scribes observed the heavens nightly and recorded the dates and locations of ominous phenomena of the moon and planets in relation to stars and constellations. The observations were arranged in monthly reports along with notable events and prices of agricultural commodities, the object being to find correlations between phenomena in the heavens and conditions on earth. These collections of omens and observations form the first empirical science of antiquity and were the basis of the first mathematical science, astronomy. For it was discovered that planetary phenomena, although irregular and sometimes concealed by bad weather, recur in limited periods within cycles in which they are repeated on nearly the same dates and in nearly the same locations. N. M. Swerdlow's book is a study of the collection and observation of ominous celestial phenomena and of how intervals of time, locations by zodiacal sign, and cycles in which the phenomena recur were used to reduce them to purely arithmetical computation, thereby surmounting the greatest obstacle to observation, bad weather. The work marks a striking advance in our understanding of both the origin of scientific astronomy and the astrological divination through which the kingdoms of ancient Mesopotamia were governed. Originally published in 1998. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

For Forty Years, Beginning With The Publication Of The First Modern English translation of the Dialogue Concerning the Two Chief World Systems, Stillman Drake was the most original and productive scholar of Galileo's scientific work of our age. During that time, he published sixteen books on Galileo, including translations of almost all the major writings, and Galileo at Work, the most comprehensive study of Galileo's life and works ever written. His collection Discoveries and Opinions on Galileo has remained in print since its appearance in 1957 and has become the most widely read of all books on Galileo. In addition to his books, Drake published about 130 papers, of which nearly 100 are on Galileo and the rest on related aspects of the history and philosophy of science. This three-volume collection includes eighty of those papers.

Drake's papers are an essential supplement to his translations and other books because it was in his papers that he wrote his most detailed technical studies of Galileo's scientific work. There is hardly a subject in Galileo's science that is not considered. Perhaps the most important are the series on mechanics and motion, in which Drake analysed Galileo's manuscript notes recording the experiments by which he discovered and confirmed the law of the acceleration of falling bodies. There are also papers on the notes in which Galileo recorded his discovery of Jupiter's satellites and on other aspects of Galileo's astronomy, including his defence of the Copernican theory.

Other papers consider Galileo's life and scientific work in general, exploring what Drake calls the 'scientific personality' of Galileo, and his scientific method and philosophy ofscience. In addition to the papers on Galileo, there are a number of papers on medieval and early modern science, principally on mechanics, and on the philosophers A.B. Johnson and J.B. Stallo, both of whom influenced Drake's own philosophy of science.

This collection is indeed a fitting tribute to the memory of one of Canada's most accomplished scholars.