Chapter I: Preface

This book makes no claim to be a biography of Lord Kelvin in the usual sense. It is an extension of an article which appeared in the _Glasgow Herald_ for December 19, 1907, and has been written at the suggestion of various friends of Lord Kelvin, in the University of Glasgow and elsewhere, who had read that article. The aim of the volume is to give an account of Lord Kelvin's life of scientific activity, and to explain to the student, and to the general reader who takes an interest in physical science and its applications, the nature of his discoveries. Only such a statement of biographical facts as seems in harmony with this purpose is attempted. But I have ventured, as an old pupil and assistant of Lord Kelvin, to sketch here and there the scene in his class-room and laboratory, and to record some of the incidents of his teaching and work.

I am under obligations to the proprietors of the _Glasgow Herald_ for their freely accorded permission to make use of their article, and to Messrs. Annan, photographers, Glasgow, and Messrs. James MacLehose & Sons, Glasgow, for the illustrations which are given, and which I hope may add to the interest of the book.

A. GRAY.

_The University_, _Glasgow_,
_May_ 20, 1908.

CONTENTS

CHAP. PAGE

I. PARENTAGE AND EARLY EDUCATION 1

II. CLASSES AT THE UNIVERSITY OF GLASGOW. FIRST SCIENTIFIC
PAPERS 13

III. UNIVERSITY OF CAMBRIDGE. SCIENTIFIC WORK AS UNDERGRADUATE 23

IV. THE MATHEMATICAL THEORY OF ELECTRICITY IN EQUILIBRIUM.
ELECTRIC IMAGES. ELECTRIC INVERSION 33

V. THE CHAIR OF NATURAL PHILOSOPHY AT GLASGOW. ESTABLISHMENT
OF THE FIRST PHYSICAL LABORATORY 61

VI. FRIENDSHIP WITH STOKES AND JOULE. EARLY WORK AT GLASGOW 79

VII. THE 'ACCOUNT OF CARNOT'S THEORY OF THE MOTIVE POWER OF
HEAT'--TRANSITION TO THE DYNAMICAL THEORY OF HEAT 99

VIII. THERMODYNAMICS AND ABSOLUTE THERMOMETRY 114

IX. HYDRODYNAMICS--DYNAMICAL THEOREM OF MINIMUM
ENERGY--VORTEX MOTION 153

X. THE ENERGY THEORY OF ELECTROLYSIS--ELECTRICAL
UNITS--ELECTRICAL OSCILLATIONS 176

XI. THOMSON AND TAIT'S 'NATURAL PHILOSOPHY'--GYROSTATIC
ACTION--'ELECTROSTATICS AND MAGNETISM' 194

XII. THE AGE OF THE EARTH 229

XIII. BRITISH ASSOCIATION COMMITTEE ON ELECTRICAL STANDARDS 244

XIV. THE BALTIMORE LECTURES 254

XV. SPEED OF TELEGRAPH SIGNALLING--LAYING OF SUBMARINE
CABLES--TELEGRAPH INSTRUMENTS--NAVIGATIONAL
INSTRUMENTS, COMPASS AND SOUNDING MACHINE 264

XVI. LORD KELVIN IN HIS CLASS-ROOM AND LABORATORY 279

XVII. PRACTICAL ACTIVITIES--HONOURS AND DISTINCTIONS--LAST
ILLNESS AND DEATH 299

CONCLUSION 305

INDEX 317

CORRIGENDUM

Page 105, line 9 from foot, for ∂e + O read ∂e + o

LIST OF ILLUSTRATIONS

_To face page_
LORD KELVIN (photogravure) _Frontispiece_
LORD KELVIN IN 1846 64
VIEW OF OLD COLLEGE 70

LORD KELVIN