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THE INVENTIONS
RESEARCHES AND WRITINGS
OF
NIKOLA TESLA
TO HIS COUNTRYMEN
IN EASTERN EUROPE THIS RECORD OF
THE WORK ALREADY ACCOMPLISHED BY
NIKOLA TESLA
IS RESPECTFULLY DEDICATED
[Illustration: Nikola Tesla]
THE INVENTIONS
RESEARCHES AND WRITINGS
OF
NIKOLA TESLA
WITH SPECIAL REFERENCE TO HIS WORK IN POLYPHASE
CURRENTS AND HIGH POTENTIAL LIGHTING
BY
THOMAS COMMERFORD MARTIN
Editor THE ELECTRICAL ENGINEER; Past-President American Institute
Electrical Engineers
1894
THE ELECTRICAL ENGINEER
NEW YORK
D. VAN NOSTRAND COMPANY,
NEW YORK.
Entered according to Act of Congress in the year 1893 by
T. C. MARTIN
in the office of the Librarian of Congress at Washington
Press of McIlroy & Emmet, 36 Cortlandt St., N. Y.
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
PART I.
POLYPHASE CURRENTS.
CHAPTER I.
BIOGRAPHICAL AND INTRODUCTORY.
As an introduction to the record contained in this volume of Mr. Tesla's
investigations and discoveries, a few words of a biographical nature
will, it is deemed, not be out of place, nor other than welcome.
Nikola Tesla was born in 1857 at Smiljan, Lika, a borderland region of
Austro-Hungary, of the Serbian race, which has maintained against Turkey
and all comers so unceasing a struggle for freedom. His family is an old
and representative one among these Switzers of Eastern Europe, and his
father was an eloquent clergyman in the Greek Church. An uncle is to-day
Metropolitan in Bosnia. His mother was a woman of inherited ingenuity,
and delighted not only in skilful work of the ordinary household
character, but in the construction of such mechanical appliances as
looms and churns and other machinery required in a rural community.
Nikola was educated at Gospich in the public school for four years, and
then spent three years in the Real Schule. He was then sent to Carstatt,
Croatia, where he continued his studies for three years in the Higher
Real Schule. There for the first time he saw a steam locomotive. He
graduated in 1873, and, surviving an attack of cholera, devoted himself
to experimentation, especially in electricity and magnetism. His father
would have had him maintain the family tradition by entering the Church,
but native genius was too strong, and he was allowed to enter the
Polytechnic School at Gratz, to finish his studies, and with the object
of becoming a professor of mathematics and physics. One of the machines
there experimented with was a Gramme dynamo, used as a motor. Despite
his instructor's perfect demonstration of the fact that it was
impossible to operate a dynamo without commutator or brushes, Mr. Tesla
could not be convinced that such accessories were necessary or
desirable. He had already seen with quick intuition that a way could be
found to dispense with them; and from that time he may be said to have
begun work on the ideas that fructified ultimately in his rotating field
motors.
In the second year of his Gratz course, Mr. Tesla gave up the notion of
becoming a teacher, and took up the engineering curriculum. His studies
ended, he returned home in time to see his father die, and then went to
Prague and Buda-Pesth to study languages, with the object of qualifying
himself broadly for the practice of the engineering profession. For a
short time he served as an assistant in the Government Telegraph
Engineering Department, and then became associated with M. Puskas, a
personal and family friend, and other exploiters of the telephone in
Hungary. He made a number of telephonic inventions, but found his
opportunities of benefiting by them limited in various ways. To gain a
wider field of action, he pushed on to Paris and there secured
employment as an electrical engineer with one of the large companies in
the new industry of electric lighting.
It was during this period, and as early as 1882, that he began serious
and continued efforts to embody the rotating field principle in
operative apparatus. He was enthusiastic about it; believed it to mark a
new departure in the electrical arts, and could think of nothing else.
In fact, but for the solicitations of a few friends in commercial
circles who urged him to form a company to exploit the invention, Mr.
Tesla, then a youth of little worldly experience, would have sought an
immediate opportunity to publish his ideas, believing them to be worthy
of note as a novel and radical advance in electrical theory as well as
destined to have a profound influence on all dynamo electric machinery.
At last he determined that it would be best to try his fortunes in
America. In France he had met many Americans, and in contact with them
learned the desirability of turning every new idea in electricity to
practical use. He learned also of the ready encouragement given in the
United States to any inventor who could attain some new and valuable
result. The resolution was formed with characteristic quickness, and
abandoning all his prospects in Europe, he at once set his face
westward.
Arrived in the United States, Mr. Tesla took off his coat the day he
arrived, in the Edison Works. That place had been a goal of his
ambition, and one can readily imagine the benefit and stimulus derived
from association with Mr. Edison, for whom Mr. Tesla has always had the
strongest admiration. It was impossible, however, that, with his own
ideas to carry out, and his own inventions to develop, Mr. Tesla could
long remain in even the most delightful employ; and, his work now
attracting attention, he left the Edison ranks to join a company
intended to make and sell an arc lighting system based on some of his
inventions in that branch of the art. With unceasing diligence he
brought the system to perfection, and saw it placed on the market. But
the thing which most occupied his time and thoughts, however, all
through this period, was his old discovery of the rotating field
principle for alternating current work, and the application of it in
motors that have now become known the world over.
Strong as his convictions on the subject then were, it is a fact that
he stood very much alone, for the alternating current had no well
recognized place. Few electrical engineers had ever used it, and the
majority were entirely unfamiliar with its value, or even its essential
features. Even Mr. Tesla himself did not, until after protracted effort
and experimentation, learn how to construct alternating current
apparatus of fair efficiency. But that he had accomplished his purpose
was shown by the tests of Prof. Anthony, made in the of winter 1887-8,
when Tesla motors in the hands of that distinguished expert gave an
efficiency equal to that of direct current motors. Nothing now stood in
the way of the commercial development and introduction of such motors,
except that they had to be constructed with a view to operating on the
circuits then existing, which in this country were all of high
frequency.
The first full publication of his work in this direction--outside his
patents--was a paper read before the American Institute of Electrical
Engineers in New York, in May, 1888 (read at the suggestion of Prof.
Anthony and the present writer), when he exhibited motors that had been
in operation long previous, and with which his belief that brushes and
commutators could be dispensed with, was triumphantly proved to be
correct. The section of this volume devoted to Mr. Tesla's inventions in
the utilization of polyphase currents will show how thoroughly from the
outset he had mastered the fundamental idea and applied it in the
greatest variety of ways.
Having noted for years the many advantages obtainable with alternating
currents, Mr. Tesla was naturally led on to experiment with them at
higher potentials and higher frequencies than were common or approved
of. Ever pressing forward to determine in even the slightest degree the
outlines of the unknown, he was rewarded very quickly in this field
with results of the most surprising nature. A slight acquaintance with
some of these experiments led the compiler of this volume to urge Mr.
Tesla to repeat them before the American Institute of Electrical
Engineers. This was done in May, 1891, in a lecture that marked, beyond
question, a distinct departure in electrical theory and practice, and
all the results of which have not yet made themselves fully apparent.
The New York lecture, and its successors, two in number, are also
included in this volume, with a few supplementary notes.
Mr. Tesla's work ranges far beyond the vast departments of polyphase
currents and high potential lighting. The "Miscellaneous" section of
this volume includes a great many other inventions in arc lighting,
transformers, pyro-magnetic generators, thermo-magnetic motors,
third-brush regulation, improvements in dynamos, new forms of
incandescent lamps, electrical meters, condensers, unipolar dynamos, the
conversion of alternating into direct currents, etc. It is needless to
say that at this moment Mr. Tesla is engaged on a number of interesting
ideas and inventions, to be made public in due course. The present
volume deals simply with his work accomplished to date.