There are a vast number of detailed and comprehensive histories, both of general science and of special departments of science. Most of these are admirable for the scientific reader, but the layman sometimes cannot see the wood for the trees. I have felt no ambition (nor competence) to add to their number, but have thought I might usefully try to describe the main lines of advance of physical science, including astronomy and mathematics but excluding all points and side-issues, in language non-technical enough to be understood by readers who have no scientific attainments or knowledge.

I hope that such a book may prove of interest to the general educated reader, perhaps also to those who are beginning the study of physics, and possibly to students of other subjects who wish to know something of how physical science has grown, what it has done, and what it can do.