POPULAR LECTURES

AND

ADDRESSES

BY

SIR WILLIAM THOMSON (BARON KELVIN)
P.R.S., LL.D., D.C.L., &c.

PROFESSOR OF NATURAL PHILOSOPHY IN THE UNIVERSITY OF GLASGOW, AND
FELLOW OF ST. PETER'S COLLEGE, CAMBRIDGE

IN THREE VOLUMES

VOL. II

GEOLOGY AND GENERAL PHYSICS

WITH ILLUSTRATIONS

London

MACMILLAN AND CO.

AND NEW YORK

1894

The Right of Translation and Reproduction is Reserved

RICHARD CLAY AND SONS, LIMITED,

LONDON AND BUNGAY.

Reclass 8-23-25 N. /. P

PREFACE.

Of the reason why Volume III. appeared before Volume II. nothing need be said here, as it was stated in the Preface to Volume III.

The first half of the present volume contains the papers relating to geological subjects referred to in that statement. The remainder of the

volume consists of lectures and addresses on various subjects of general physics, given between 1866 and the end of 1893, which have not been

included in Vols. I. or III.

UNIVERSITY, Glasgow.

February 2, 1894.

KELVIN.