San Francisco Call
November 13, 1898
TESLA'S latest electrical wonder is out. It is out because he has just received patents on it in this and other countries.
What Tesla proposes to do now is to transmit almost any amount of power almost any distance without wires, and without loss. Although moving ships at sea may use the system for propulsion it is mainly intended for use on land.
To illustrate the anticipated results in the most concrete form it is proposed, for instance, that water power shall generate a great quantity of electricity on the lower courses of streams coming from the Sierras; that this electricity shall be conducted to a balloon arrangement floating a mile or two above the earth; that there shall be in San Francisco a similar balloon high above the city and that all the electrical energy conducted to the first balloon shall pass without loss and without wires to the balloon over the city, from which it shall descend to turn wheels and light lamps, etc.
A secondary result would seem to be that ships minus boilers and minus coal shall plow their way from the Golden Gate to Puget Sound, their churning propellers being driven by motors which draw their energy through the air from stations arranged every hundred miles or so along the shore.
This may seem a crazy idea to some people, but then it was a more crazy idea once that a man's voice should be heard 2000 miles away and that a waterfall should turn a mill a hundred miles away, and besides Nikola Tesla says so and he is acknowledged as one of the very best electric experts in the country.
In one sense Tesla is a greater wizard than Edison. They are twin wizards in the wondrous field of electrical science, but they are wholly unlike. Edison is wholly practical and he cares for nothing that he cannot make a commercial success. His spur is not devotion to science as it was with Franklin, Faraday, Volta, Galvani and the rest. Tesla is rather Edison's reverse as a genius. He plunges into electrical mystery and seeks scientific facts, phenomena, laws and principles rather than patents though he looks out for the patents when they are in sight.
Young Tesla has startled the world about as much as has Edison, but you don't find his name on the patent plates of as many machines about town. He made electrical engineers marvel by smilingly passing a million volts of electricity through his body and he showed them how to light a room brilliantly with a simple empty glass tube which he held in his hand or laid on the table without any connecting wires.
In various ways he has led the scientific world far toward the final mystery of this "form of radiation." This latest advance of his is both scientific and practical.
"Tesla's System of electric power transmission through natural media" is the descriptive title of this latest invention of his. transmitterreceiver
This at once suggests the new telegraphy without wires, which promises to be a commercial feature of everyday life to-morrow or next day, but the one system is wholly different from the other.
In the wireless telegraphy an apparatus sends out in all directions through air, buildings, earth and water a series of "Hertzian waves" as a lighthouse lamp sends out light waves. The length and frequency are regulated and the receiving apparatus, if adapted to these waves, responds as one tuning fork will to its like. In this case the electrical phenomena proceed in all directions like sound or ripples from where a stone strikes in the water.
Tesla, however, proposes to generate energy at one point and pass it all without loss through the air direct to a distant point, where it may be used for light or power. A comprehension of his invention depends upon an understanding of "voltage."
An electric current may be large in quantity and low in intensity or small in quantity and high in intensity as a stream of water be large in volume and slow of motion or may be small and rapid. A stream of water an inch in diameter will exert more power than a small river if the pressure is great enough.
In handling electricity quantity is reduced to intensity and the reverse by means of "transformers." In long-distance transmission of power the energy is transformed to a high intensity or voltage and then sent over the wires, and where it is received it is again transformed to a lower voltage and greater quantity for use.
Here is another preparatory illustration. Most people have seen electric sparks jump from one brass ball to another in electrical apparatus. The distance these sparks will jump depends not on the amount of electricity generated but on its intensity or voltage.
Now, there are two things which mainly underlie Tesla's new scheme. One is the production of voltages before hardly dreamed of, and the other is the increased conductivity of the air, when it is rarefied as it is at high altitudes.
Up to date 15,000 volts has been the measure of the intensity at which electric power has been transmitted over copper wires, though now they are talking of doubling it. Tesla proposes to transmit it without wires at 2,500,000 volts or more. At this voltage a given quantity transmitted would produce about 200 times the ordinary amount of power when reduced with transformers.
It is a well-known laboratory fact that rarefied air is a conductor of electricity, though one of much resistance. The Crookes tubes of X ray fame depend on this principle. With one sweep Tesla takes this principle from the laboratories where, only, men have put it to use, and goes up to the clouds with it. He produces a wonderful voltage that will jump an enormous distance in every-day air, and proposes to take it in balloons up to where the air is a sort of natural Crookes tube. In such an altitude it will jump long distances to another terminal, he says, the layer of heavy air below being a non-conductor and resisting it like the rubber wrapping of a wire, for ordinary air is not a good conductor.
Tesla is the pioneer of high voltages. Some time ago he invented an "oscillator" a purely Tesla contrivance, for this purpose. He has been making them bigger and bigger and his last one gets up to 2,500,000 volts. The accompanying illustration shows his latest oscillator in action.
The diagrams illustrate the theory of the apparatus. In the transmitting apparatus A is an insulated high tension coil about a magnetic core. C is a second coil of larger wire. The terminals of both coils are shown. G is the generator or source of current. D is a balloon acting as a terminal itself or a terminal supported by a balloon to which the current passes. The current is supposed to pass through the rarefied upper air from D to D1, a receiving balloon at a great distance. The primary and secondary coils of the receiving apparatus are the reverse of the transmitter. L and M indicate lamps and motors to be energized by the transmitted current.
In the long descriptive text accompanying the inventor's application for a patent it is said that the invention comprises a novel method for the transmission of electrical energy with out the employment of metallic line conductors, but the results arrived at are of such character and magnitude as compared with any heretofore secured as to render indispensable the employment of means and the utilization of effect essentially different in their characteristics and actions from those before used or investigated.
The systems depend, he says, on "exclusively high pressures," but he has devised means to generate with safety and ease pressures measured by millions of volts. Then he states some thing that electrical engineers know mighty little about. He says: transmitterreceiver
"First, that with electrical pressures of the magnitude and character which I have made it possible to produce, the ordinary atmosphere becomes, in a measure, capable of service as a true conductor; second, that the conductivity of the air increases so materially with the increase of electrical pressure and degree of rarefaction that it becomes possible to transmit through even moderately rarefied strata of the atmosphere electrical energy up to practically any amount and to any distance."
If Tesla can bring electrical energy through the air in "any amount and to any distance" he can get a big contract out here in California next week. But for all anybody knows we will soon be sending up balloons about the bay to catch the thunderbolts hurled from balloons away in the mountains, and be laughing at the poor colliers that will have to go into the lumber trade.
"If there be high mountains in the vicinity," says Mr. Tesla, "the terminals should be at a greater height."
Electrical engineers seen yesterday declined to discuss this wonderful proposition for publication just yet, but said that they had no doubt that something of the sort would be done one of these days. It is, in fact, quite likely that future generations will look back with curious interest on these days where people used poles and wires for electricity and pictures and samples will be stowed in museums like old armor and the first steam engines.
Mr. Tesla's invention for handling vessels at sea without there being anybody on board differs slightly from the apparatus for transmitting power across land with out the use of wires. In the latter the principle of overcoming resistance by placing the electrode high in air where there is little resistance is made use of. Just what principle is used in the movement of vessels is not clearly explained in the telegraphic reports from the inventor, but it would appear to be some application of the principle that causes an X ray to glow even when removed several feet from the static machine. But whatever it is it is one of the greatest wonders of the age and surely destined to revolutionize warfare.
In speaking of his ship moving and handling invention Tesla said:
"Hitherto the only means of controlling the movements of a vessel from a distance have been supplied through the medium of a flexible conductor, such as an electric cable, but this system is subject to obvious limitations, such as are imposed by the length, weight and strength of the conductor which can be practically used; by the difficulty of maintaining with safety the high speed of the vessel or changing the direction of her movements with rapidity; the necessity of effecting the control from a point which is practically fixed, and from many other drawbacks which are inseparably connected with such a system.
"The plan which I have perfected involves none of these objections, for I am enabled by the use of my invention to employ any means of propulsion to impart to the moving body or vessel the highest possible speed, to control the operation of its machinery and to direct its movements from either a fixed point or from a body moving and changing its direction, however rapidly, and to maintain this control over great distances without any artificial connections between the vessel and the apparatus governing its movements, and without such restrictions as these must necessarily impose."