Many of the preceding volumes of this well-known series may have possessed a wider interest, but few, if any, are of greater value, or will more profoundly influence the progress of seismology, than that which is now before us. This evidently is a work which is neither to be “tasted” nor “swallowed,” nor even to be “chewed and digested.” It is intended for those who make books, not for those who read them. It will be the parent of many papers. For in these somewhat unattractive-looking pages are gathered materials for the harmonic analyzer and facts for the student of terrestrial evolution. Only the labour is required, and that will soon be forthcoming, and we shall know something about the laws which govern the distribution of earthquakes in space and time, at any rate in the country where they have been most widely and successfully studied.