First published in 1928, as the second edition of a 1924 original, this book presents a series of extracts illustrating the development of scientific thought. The text is divided into three sections: 'Cosmogony', 'The Atomic Theory', and 'The Theory of Evolution'. Within each section the extracts run chronologically, revealing the development of the subject in the thought of succeeding ages. Illustrative figures are also included. This book will be of value to anyone with an interest in the history of science.