Your letter has
vivified the memory of our beginning friendship, of the first
imperfect attempts and undeserved successes, of kindnesses and
misunderstandings. It has brought painfully to my mind the greatness
of early expectations, the quick flight of time, and alas! the
smallest of realizations. The following lines which, but for your
initiative, might not have been given to the world for a long time
yet, are an offering in the friendly spirit of old, and my best
wishes for your future success accompany them.
Various reasons, not the least of which was the help proffered by my friend Leonard E. Curtis and the Colorado Springs Electric Company, determined me to select for my experimental investigations the large plateau, two thousand meters above sea-level, in the vicinity of that delightful resort, which I reached in May, 1899.
I had not been there but a few days when I congratulated myself on the happy choice and I began the task, for which I had long trained myself, with a grateful sense and full of inspiring hope. The perfect purity of the air, the unequaled beauty of the sky, the imposing sight of a high mountain range, the quiet and restfulness of the place—all around contributed to make the conditions for scientific observation ideal.
To this was added the exhilarating influence of a glorious climate and a singular sharpening of the senses. In those regions the organs undergo perceptible physical changes.
The eyes assume an extraordinary limpidity, improving vision; the ears dry out and become more susceptible to sound.
Objects can be clearly distinguished there at
distances such that I prefer to have them told by some-one else, and
I have heard—this I can venture to vouch for—the claps of thunder
700 and 800 kilometers [roughly 400 to 500 miles] away. I might have
done better still, had it not been tedious to wait for the sounds to
arrive, in definite intervals, as heralded precisely by an
electrical indicating apparatus—nearly an hour before.
The variations of potential gave rise to electric surgings in the primary; these generated secondary currents, which in turn affected the sensitive device and recorder in proportion to their intensity. The earth was found to be, literally, alive with electrical vibrations, and soon I was deeply absorbed in this interesting investigation. No better opportunities for such observations as I intended to make could be found anywhere. Colorado is a country famous for the natural displays of electric force. In that dry and rarefied atmosphere the sun's rays beat the objects with fierce intensity.
I raised steam, to a dangerous pressure, in barrels filled with concentrated salt solution, and the tin-foil coatings of some of my elevated terminals shriveled up in the fiery blaze. An experimental high-tension transformer, carelessly exposed to the rays of the setting sun, had most of its insulating compound melted out and was rendered useless.
Aided by the dryness and rarefaction of the air, the
water evaporates as in a boiler, and static electricity is developed
in abundance. Lightning discharges are, accordingly, very frequent
and sometimes of inconceivable violence. On one occasion
approximately twelve thousand discharges occurred in two hours, and
all in a radius of certainly less than fifty kilometers from the
laboratory. Many of them resembled gigantic trees of fire with the
trunks up or down. I never saw fire balls, but as a compensation for
my disappointment I succeeded later in determining the mode of their
formation and producing them artificially.
One night, as I was walking home with an assistant,
meditating over these experiences, I was suddenly staggered by a
thought. Years ago, when I wrote a chapter of my lecture before the
Franklin Institute and the National Electric Light Association, it
had presented itself to me, but I had dismissed it as absurd and
impossible. I banished it again. Nevertheless, my instinct was
aroused and somehow I felt that I was nearing a great revelation.
My observations were now greatly facilitated and rendered more accurate by the experiences already gained. I was able to handle my instruments quickly and I was prepared. The recording apparatus being properly adjusted, its indications became fainter and fainter with the increasing distance of the storm, until they ceased altogether. I was watching in eager expectation.
Sure enough, in a little while the indications began again, grew stronger and stronger and, after passing through a maximum, gradually decreased and ceased once more.
Many times, in regularly recurring intervals, the same actions were repeated until the storm which, as evident from simple computations, was moving with nearly constant speed, had retreated to a distance of about three hundred kilometers. Nor did these strange actions stop then, but continued to manifest themselves with undiminished force.
Subsequently, similar observations were also made by
my assistant, Mr. Fritz Lowenstein, and shortly afterward several
admirable opportunities presented themselves which brought out,
still more forcibly, and unmistakably, the true nature of the
wonderful phenomenon. No doubts whatever remained: I was observing
This is, essentially, a circuit of very high self-induction and small resistance which in its arrangement, mode of excitation and action, may be said to be the diametrical opposite of a transmitting circuit typical of telegraphy by Hertzian or electromagnetic radiations. It is difficult to form an adequate idea of the marvelous power of this unique appliance, by the aid of which the globe will be trans-formed.
The electromagnetic radiations being reduced to an
insignificant quantity, and proper conditions of resonance
maintained, the circuit acts like an immense pendulum, storing
indefinitely the energy of the primary exciting impulses and
impressions upon the earth and its conducting atmosphere uniform
harmonic oscillations of intensities which, as actual tests have
shown, may be pushed so far as to surpass those attained in the
natural displays of static electricity.
The influence of this principle on the transmission of intelligence, and electrical energy in general, cannot as yet be estimated, for the art is still in the embryonic stage; but many thousands of simultaneously telegraphic and telephonic messages, through one single conducting channel, natural or artificial, and without serious mutual interference, are certainly practicable, while millions are possible.
On the other hand, any desired degree
of individualization may be secured by the use of a great number of
cooperative elements and arbitrary variation of their distinctive
features and order of succession. For obvious reasons, the principle
will also be valuable in the extension of the distance of
The experimental station at Colorado Springs
showing the structure used to
deter-mine the rate of incremental capacity with reference to the
Much has already been done towards making my system commercially available, in the transmission of energy in small amounts for specific purposes, as well as on an industrial scale.
The results attained by me have made my scheme of intelligence transmission, for which the name of "World Telegraphy" has been suggested, easily realizable. It continues, I believe, in its principle of operation, means employed and capacities of application, a radical and fruitful departure from what has been done heretofore.
I have no doubt that it will prove very efficient in enlightening the masses, particularly in still uncivilized countries and less accessible regions, and that it will add materially to general safety, comfort and convenience, and maintenance of peaceful relations. It involves the employment of a number of plants, all of which are capable of transmitting individualized signals to the uttermost confines of the earth.
Each of them will be preferably located near some import center of civilization and the news it receives through any channel will be flashed to all points of the globe. A cheap and simple device, which might be carried in one's pocket, may then be set up somewhere on sea or land, and it will record the world's news or such special messages as may be intended for it.
Thus the entire earth will be converted into a huge brain, as it were, capable of response in every one of its parts.
Tesla's tower at Wardenclyffe
for sending messages across the Atlantic
and electricity into the
atmosphere as it appeared in 1904.
Since a single plant of
but one hundred horse-power can operate hundreds of millions of
instruments, the system will have a virtually infinite working
capacity, and it must immensely facile Tate and cheapen the
transmission of intelligence.
This enormous rate of energy delivery,
approximately twice that of the combined falls of Niagara, is
obtainable only by the use of certain artifices, which I shall make
known in due course.
Another valuable application will be the driving of clocks and other such apparatus.
These clocks will be exceedingly simple, will require absolutely no attention and will indicate rigorously correct time. The idea of impressing upon the earth American time is fascinating and very likely to become popular. There are innumerable devices of all kinds which are either now employed or can be supplied, and by operating them in this manner I may be able to offer a great convenience to the whole world with a plant of no more than ten thousand horse-power.
The introduction of this system will give opportunities for invention and manufacture such as never been presented themselves before.
Tesla's perfected system of wireless transmission with four tuned circuits was described
in U.S. patent numbers 645,576 (March 20, 1900) and 649,621 (May 15, 1900).
The applications were filed on September 2, 1897.
Knowing the far-reaching importance of this first attempt and its effect upon future development, I shall proceed slowly and carefully.
Experience has taught me not to assign a term
to enterprises the consummation of which is not wholly dependent on
my own abilities and exertions. But I am hopeful that these great
realizations are not far off, and I know that when this first work
is completed they will follow with mathematical certitude.
When the first plant is inaugurated and it is shown that a telegraphic message, almost as secret and non-interferable as a thought, can be transmitted to any terrestrial device, the sound of the human voice, with all its intonations and inflections, faithfully and instantly reproduced at any other point of the globe, the energy of a waterfall made available for supplying light, heat or motive power, anywhere—on sea, or land, or high in the air— humanity will be like an ant heap stirred up with a stick.
See excitement coming!