This volume contains an English translation of Galileo's seminal work, 'Two Sciences'. Writing to his faithful friend Elia Diodati, Galileo speaks of the ''New Sciences'' which he has in mind to print as being ''superior to everything else of mine hitherto published''; elsewhere he says ''they contain results which I consider the most important of all my studies''. This fascinating exposition will greatly appeal to those with a keen interest in Galileo and the history and development of astronomy, and it will make for a great addition to collections of allied literature. The chapters of this volume include: A Brief History of Astronomy, Translators' Preface, Introduction, To the Most Illustrious Lord Count of Noailles, The Publisher to the Reader, Two New Sciences by Galileo, First Day, Second Day, Third Day, and Fourth Day. This antiquarian volume is being republished now complete with a new introduction on the history of astronomy.