A Source Book for the History of Mathematics, but one which offers a different perspective by focusing on algorithms. With the development of computing has come an awakening of interest in algorithms. Often neglegted by historians and modern scientists, more concerned with the nature of concepts, algorithmic procedures turn out to have been instrumental in the development of fundamental ideas: practice led to theory just as much as the other way round. The purpose of this book is to offer a historical background to contemporary algorithmic practice. Each chapter centres around a theme, more or less in chronological order, and the story is told through the reading of over 200 original texts, faithfully reproduced. This provides an opportunity for the reader to sit alongside such mathematicians as Archimedes, Omar Khayyam, Newton, Euler and Gauss as they explain their techniques. The book ends with an account of the development of the modern concept of algorithm.