To the theses just enumerated Buffon added what he called the "monuments," or what Hugh Miller, a century later, more aptly described as the Testimony of the Rocks. From a consideration of all these things, Buffon at length arrived at his succession of the Epochs, or Seven Ages of Nature, namely: (1) the Age of fluidity, or incandescence, when the earth and planets assumed their shape; (2) the Age of cooling, or consolidation, when the rocky interior of the earth and the great vitrescible masses at its surface were formed; (3) the Age when the waters covered the face of the earth; (4) the Age when the waters retreated and volcanoes became active; (5) the Age when the elephant, hippopotamus, rhinoceros, and other giants roamed through the northern hemisphere; (6) the Age of the division of the land into the vast areas now styled the Old and the New Worlds; and (7) the Age when Man appeared. ROBERT CHAMBERS Vestiges of Creation Robert Chambers was born in Peebles, Scotland, July 10, 1802, and died at St. Andrews on March 17, 1871. He was partner with his brother in the publishing firm of W. & R. Chambers, was editor of "Chambers's Journal," and was author of several works when he published anonymously, in October 1844, the work by which his name will always be remembered, "Vestiges of the Natural History of Creation." His previous works, some thirty in number, did not deal with science, and his labour in preparing his masterpiece was commensurate with the courage which such an undertaking involved. When the book was published, such interest and curiosity as to its authorship were aroused that we have to go back to the publication of "Waverley" for a parallel. Little else was talked about in scientific circles. The work was violently attacked by many hostile critics, F.W. Newman, author of an early review, being a conspicuous exception. In the historical introduction to the "Origin of Species," Darwin speaks of the "brilliant and powerful style" of the "Vestiges," and says that "it did excellent service in this country in calling attention to the subject, in removing prejudice, and in thus preparing the ground for the reception of analogous views." Darwin's idea of selection as the key to the history of species does not occur in the "Vestiges," which belongs to the Lamarckian school of unexamined belief in the hereditary transmission of the effects of use and disuse. _I.--The Reign of Universal Law_