Chapter I: Preface

The electrical problems of the present day lie largely in the economical transmission of power and in the radical improvement of the means and methods of illumination. To many workers and thinkers in the domain of electrical invention, the apparatus and devices that are familiar, appear cumbrous and wasteful, and subject to severe limitations. They believe that the principles of current generation must be changed, the area of current supply be enlarged, and the appliances used by the consumer be at once cheapened and simplified. The brilliant successes of the past justify them in every expectancy of still more generous fruition.

The present volume is a simple record of the pioneer work done in such departments up to date, by Mr. Nikola Tesla, in whom the world has already recognized one of the foremost of modern electrical investigators and inventors. No attempt whatever has been made here to emphasize the importance of his researches and discoveries. Great ideas and real inventions win their own way, determining their own place by intrinsic merit. But with the conviction that Mr. Tesla is blazing a path that electrical development must follow for many years to come, the compiler has endeavored to bring together all that bears the impress of Mr. Tesla's genius, and is worthy of preservation. Aside from its value as showing the scope of his inventions, this volume may be of service as indicating the range of his thought. There is intellectual profit in studying the push and play of a vigorous and original mind.

Although the lively interest of the public in Mr. Tesla's work is perhaps of recent growth, this volume covers the results of full ten years. It includes his lectures, miscellaneous articles and discussions, and makes note of all his inventions thus far known, particularly those bearing on polyphase motors and the effects obtained with currents of high potential and high frequency. It will be seen that Mr. Tesla has ever pressed forward, barely pausing for an instant to work out in detail the utilizations that have at once been obvious to him of the new principles he has elucidated. Wherever possible his own language has been employed.

It may be added that this volume is issued with Mr. Tesla's sanction and approval, and that permission has been obtained for the re-publication in it of such papers as have been read before various technical societies of this country and Europe. Mr. Tesla has kindly favored the author by looking over the proof sheets of the sections embodying his latest researches. The work has also enjoyed the careful revision of the author's friend and editorial associate, Mr. Joseph Wetzler, through whose hands all the proofs have passed.

DECEMBER, 1893.

T. C. M.

CONTENTS.

PART I.

POLYPHASE CURRENTS.

CHAPTER I.
BIOGRAPHICAL AND INTRODUCTORY. 3

CHAPTER II.
A NEW SYSTEM OF ALTERNATING CURRENT MOTORS AND TRANSFORMERS. 7

CHAPTER III.
THE TESLA ROTATING MAGNETIC FIELD.--MOTORS WITH CLOSED
CONDUCTORS.--SYNCHRONIZING MOTORS.--ROTATING FIELD TRANSFORMERS. 9

CHAPTER IV.
MODIFICATIONS AND EXPANSIONS OF THE TESLA POLYPHASE SYSTEMS. 26

CHAPTER V.
UTILIZING FAMILIAR TYPES OF GENERATORS OF THE CONTINUOUS CURRENT
TYPE. 31

CHAPTER VI.
METHOD OF OBTAINING DESIRED SPEED OF MOTOR OR GENERATOR. 36

CHAPTER VII.
REGULATOR FOR ROTARY CURRENT MOTORS. 45

CHAPTER VIII.
SINGLE CIRCUIT, SELF-STARTING SYNCHRONIZING MOTORS. 50

CHAPTER IX.
CHANGE FROM DOUBLE CURRENT TO SINGLE CURRENT MOTORS. 56

CHAPTER X.
MOTOR WITH "CURRENT LAG" ARTIFICIALLY SECURED. 58

CHAPTER XI.
ANOTHER METHOD OF TRANSFORMATION FROM A TORQUE TO A SYNCHRONIZING
MOTOR. 62

CHAPTER XII.
"MAGNETIC LAG" MOTOR. 67

CHAPTER XIII.
METHOD OF OBTAINING DIFFERENCE OF PHASE BY MAGNETIC SHIELDING. 71

CHAPTER XIV.
TYPE OF TESLA SINGLE-PHASE MOTOR. 76

CHAPTER XV.
MOTORS WITH CIRCUITS OF DIFFERENT RESISTANCE. 79

CHAPTER XVI.
MOTOR WITH EQUAL MAGNETIC ENERGIES IN FIELD AND ARMATURE. 81

CHAPTER XVII.
MOTORS WITH COINCIDING MAXIMA OF MAGNETIC EFFECT IN ARMATURE AND
FIELD. 83

CHAPTER XVIII.
MOTOR BASED ON THE DIFFERENCE OF PHASE IN THE MAGNETIZATION OF
THE INNER AND OUTER PARTS OF AN IRON CORE. 88

CHAPTER XIX.
ANOTHER TYPE OF TESLA INDUCTION MOTOR. 92

CHAPTER XX.
COMBINATIONS OF SYNCHRONIZING MOTOR AND TORQUE MOTOR. 95

CHAPTER XXI.
MOTOR WITH A CONDENSER IN THE ARMATURE CIRCUIT. 101

CHAPTER XXII.
MOTOR WITH CONDENSER IN ONE OF THE FIELD CIRCUITS. 106

CHAPTER XXIII.
TESLA POLYPHASE TRANSFORMER. 109

CHAPTER XXIV.
A CONSTANT CURRENT TRANSFORMER WITH MAGNETIC SHIELD BETWEEN
COILS OF PRIMARY AND SECONDARY. 113

PART II.

THE TESLA EFFECTS WITH HIGH FREQUENCY AND HIGH POTENTIAL CURRENTS.

CHAPTER XXV.
INTRODUCTORY.--THE SCOPE OF THE TESLA LECTURES. 119

CHAPTER XXVI.
THE NEW YORK LECTURE. EXPERIMENTS WITH ALTERNATE CURRENTS OF VERY
HIGH FREQUENCY, AND THEIR APPLICATION TO METHODS OF ARTIFICIAL
ILLUMINATION, MAY 20, 1891. 145

CHAPTER XXVII.
THE LONDON LECTURE. EXPERIMENTS WITH ALTERNATE CURRENTS OF HIGH
POTENTIAL AND HIGH FREQUENCY, FEBRUARY 3, 1892. 198

CHAPTER XXVIII.
THE PHILADELPHIA AND ST. LOUIS LECTURE. ON LIGHT AND OTHER HIGH
FREQUENCY PHENOMENA, FEBRUARY AND MARCH, 1893. 294

CHAPTER XXIX.
TESLA ALTERNATING CURRENT GENERATORS FOR HIGH FREQUENCY. 374

CHAPTER XXX.
ALTERNATE CURRENT ELECTROSTATIC INDUCTION APPARATUS. 392

CHAPTER XXXI.
"MASSAGE" WITH CURRENTS OF HIGH FREQUENCY. 394

CHAPTER XXXII.
ELECTRIC DISCHARGE IN VACUUM TUBES. 396

PART III.

MISCELLANEOUS INVENTIONS AND WRITINGS.

CHAPTER XXXIII.
METHOD OF OBTAINING DIRECT FROM ALTERNATING CURRENTS. 409

CHAPTER XXXIV.
CONDENSERS WITH PLATES IN OIL. 418

CHAPTER XXXV.
ELECTROLYTIC REGISTERING METER. 420

CHAPTER XXXVI.
THERMO-MAGNETIC MOTORS AND PYRO-MAGNETIC GENERATORS. 424

CHAPTER XXXVII.
ANTI-SPARKING DYNAMO BRUSH AND COMMUTATOR. 432

CHAPTER XXXVIII.
AUXILIARY BRUSH REGULATION OF DIRECT CURRENT DYNAMOS. 438

CHAPTER XXXIX.
IMPROVEMENT IN DYNAMO AND MOTOR CONSTRUCTION. 448

CHAPTER XL.
TESLA DIRECT CURRENT ARC LIGHTING SYSTEM. 451

CHAPTER XLI.
IMPROVEMENT IN UNIPOLAR GENERATORS. 465

PART IV.

APPENDIX: EARLY PHASE MOTORS AND THE TESLA OSCILLATORS.

CHAPTER XLII.
MR. TESLA'S PERSONAL EXHIBIT AT THE WORLD'S FAIR. 477

CHAPTER XLIII.
THE TESLA MECHANICAL AND ELECTRICAL OSCILLATORS. 486