REVISER'S PREFACE.
By the courtesy of the authors and publishers of this book, I have beien given an opportunity to make a rather extensive revision of it. The principal changes which have been made, besides such slight corrections or supplementary statements as seemed necessary, are, an entire rearrangement and enlargement of the mechanics, and the addition of a discussion of the kinetic theory of matter and of a treatment of magnetism and electricity by the method of tubes of force. The omissions have been largely of statements that would naturally be made by the lecturer or of demonstrations in which the results reached did not warrant the expenditure of time and trouble necessary to master them. I trust that I have adhered throughout to the original design of the authors.
During the last few years I have been using with my classes Selby's "Elementary Mechanics of Solids and Fluids," and have availed myself in many places in the present revision of the suggestions which I received from that admirable book. The additions to the Magnetism and Electricity are based upon the treatment of the subject by J. J. Thomson in his "Elementary Theory of Electricity aud Magnetism."
W. F. Magie.
Princeton University,
February, 1897.
