by Nikola Tesla
English Mechanic and World of Science, May 3, 1907, p. 296.
Just at this time, when all efforts towards peaceful arbitration notwithstanding, the nations are preparing to expend immense sums in the design and construction of monstrous battleships, it may be useful to bring to the attention of the general public a singular means for naval attack and defense, which the telautomatic art has made possible, and which is likely to become a deciding factor in the near future.
A few remarks on this invention, of which the wireless torpedo is but a special application, are indispensable to the understanding and full appreciation of the naval principle of destruction.
The telautomatic art is the result of endeavors to produce an automaton capable of moving and acting as if possessed of intelligence and distinct individuality. Disconnected from its higher embodiment, an organism, such as a human being, is a heat - or thermodynamic engine - comprising: (1) a complete plant for receiving, transforming, and supplying energy; (2) apparatus for locomotion and other mechanical performance; (3) directive organs; and (4) sensitive instruments responsive to external influences, all these parts constituting a whole of marvelous perfection.
The ambient medium is alive with movement and energy, in a state of unceasing agitation, which is beyond comprehension. Strangely enough, to most of this terrible turmoil the human machine is insensible. The automaton does not feel the weight of the atmosphere crushing him with a force of 16 tons. He is unaffected by the shower of particles shooting through his body of cloud and the hurricane of finer substance rushing through him with the speed of light. He is unconscious that he is being whisked through space at the fearful rate of 70,000 miles an hour. But when gentle waves of tight or sound strike him his eye and ear respond, his resonant nerve fibers transmit the vibrations and his muscles contract and relax. Thus, like a float on a turbulent sea, swayed by external influences, he moves and acts. The average person is not aware of this constant dependence on his environment, but a trained observer has no difficulty in locating the primary disturbance, which prompts him into action, and continued exercise soon satisfies him that virtually all of his purely mechanical motions are caused by visual impressions, directly or indirectly received.
USING THE PRINCIPLES OF HUMAN ACTION.
A machine of such inconceivable complexity as the body of an organized being, capable of an infinite variety of actions, with controlling organs supersensitive, responsive to influences almost immaterial, cannot be manufactured by man; but the mechanical principles involved in the working of the living automaton are also applicable to an inanimate engine, however crude.
An automobile boat was first employed to carry out the idea. Its storage battery and motor furnished the power; the propeller and rudder, respectively, served as locomotive and directive organs, and a very delicate electrical device, actuated by a circuit tuned to a distant transmitter, took the place of the ear. This mechanism followed perfectly the wireless signals or comments of the operator in control of the transmitter, performing every movement and action as if it had been gifted with intelligence.
The next step was to individualize the machine. The attunement of the controlling circuits gave it a special feature, but this was not sufficiently distinctive. An individuality implies a number of characteristic traits which, though perhaps extant elsewhere, are unique in that particular combination. Here again the animated automaton, with its nerve-signal system, was coarsely imitated. The action of the delicate device--the ear--was made dependent on a number of sensitized receiving circuits, each recognizable by its own free vibrations, and all together by the character of their operative combination. Correspondingly the transmitter was designed to emit a wave-complex exactly matching the combination in the number and pitch of individual vibrations, their groupment and order of succession.
WONDERS OF THE NEW TELAUTOMATON.
That much is done, but more is to come. A mechanism is being perfected which without operator in control, left to itself, will behave as if endowed with intelligence of its own. It will be responsive to the faintest external influences and from these, unaided, determine its subsequent actions as if possessed of selective qualities, logic, and reason. It will perform the duties of an intelligent slave. Many of us will live to see Bulwer's dream realized.
The reader for whom the preceding short explanation of this novel art is intended may think it simple and easy of execution, but it is far from being so. It has taken years of study and experiment to develop the necessary methods and apparatus, and five inventions, all more or less fundamental and difficult to practice, must be employed to operate successfully and individualized telautomaton.
Such a novel engine of war - a vessel of any kind, submarine or aerial – carrying an agent of unlimited potency of destruction, with no soul aboard, yet capable of doing all it is designed for, as if fully equipped with a fearless crew in command of its captain, must needs bring on a revolution -in the present means of attack and defense.
Since ages human ingenuity has been bent upon inventing infernal machines. Of these the modern cannon has been so far the most remarkable. A 12 in. gun charged with cordite is said to hurt a projectile of 850 lb. with the initial velocity of nearly 2,900 ft. per second, imparting to it the energy of 110,000,000 ft. lb. Were it not for the resistance of the air such a projectile would travel about fifty miles before striking the ground. It would take 3,300 H. P. more than a minute to accumulate its mechanical energy. Bear in mind, however, that all this energy is imparted to the projectile while it is being urged through the gun-barrel with a mean force of 1,100 tons. If the barrel is 50 ft. long and the average velocity through it 1,500 ft. per second, the whole energy is transferred to a moving mass in 1/30th of a second; hence the rate of performance is 1,800 times the above-that is about 6,000,000 H.P. This seems wonderful indeed, but is nothing as compared with rates obtained by other means. Electricity can be stored in the form of explosive energy of a violence against which the detonation of cordite is but a breath. With a magnifying transmitter as diagrammatically illustrated, rates of 25,000,000 H.P. have already been obtained. A similar and much improved machine, now under construction, will make it possible to attain maximum explosive rates of over 800,000,000 H.P., twenty times the performance of the Dreadnought's broadside of eight 12 in. guns simultaneously fired. These figures are so incredible that astronomers unacquainted with the marvelous appliance have naturally doubted the practicability of signaling to Mars. In reality, by its means the seemingly visionary project has been reduced to a rational engineering problem.
The time is not far distant when all the tremendous wastes of war will be stopped, and then, if there are battles, they wilt be fought with waterpower and electrical waves. That humanity is moving fast towards this realization is evident from many indications.
What is most to be regretted in the present war regime is that the effort of so many exquisite intelligences must be uneconomical1y applied, since it cannot be entirely governed by the wavering struggle of opposing principles. This feverish striving to meet the instant demand, to create type after type, one to devour the other, to merge into one contrasting element, leads, like a nightmare, from one to another absurdity. Such a monstrosity is the latest creation of the naval constructor - a 20,000 ton battleship. In theory it is condemned by competent authorities.
Everything points to the development of a small vessel with internal combustion engines, extreme speed, and few weapons of great destructiveness. But the new leviathan is admirably adapted to the practical requirements of the day. In attack it could alone annihilate a nation's fleet. It is equally effective in defense. If equipped with proper acoustic and electrical appliances it has little to fear from a submarine, and an ordinary torpedo wilt scarcely hurt it. That is why the first of these monsters, built in England, has been name Dreadnought. Now, there is a novel means for attacking a fortress of this kind, from shore or on the high seas, against which alt its gun-power and armour resistance are of no avail. It is the tidal wave.
WHAT THE TESLA TIDAL WAVE WILL DO.
Such a wave can be produced with twenty or thirty tons of cheap explosive carried to its destination and ignited by a non-interferible telautomaton.
The tidal disturbance, as here considered, is a peculiar hydrodynamic phenomenon, in many respects different from the commonly occurring, characterized by a rhythmical succession of waves. It consists generally of but a single advancing swell succeeded by a hollow, the water if not otherwise agitated being perfectly calm in front and very nearly so behind. The wave is produced by some sudden explosion or upheaval, and is, as a rule, asymmetrical for a large part of its course. Those who have encountered a tidal wave must have observed that the sea rises rather slowly, but the descent into the trough is steep. This is due to the fact that the water is lifted, possibly very slowly, under the action of a varying force, great at first, but dying out quickly, while the raised mass is urged downward by the constant force of gravity. When produced by natural causes these waves are not very dangerous to ordinary vessels, because the disturbance originated at a great depth.
To give a fairly accurate idea of the efficacy of this novel means of destruction, particularly adapted for the coast defense, it may be assumed that thirty tons of nitroglycerine compound, as dynamite, be employed to create the tidal disturbance. This material, weighing about twice as much as water, can be stored in a cubical tank 8 ft. each way, or a spherical vessel of 10 ft. diameter. The reader will now understand that this charge is to be entrusted to a non-interferable telautomaton, heavily protected, and partly submerged or submarine, which is under perfect control of a skilled operator far away. At the propitious moment the signal is given, the charge sunk to the proper depth and ignited.
The water is incompressible. The hydrostatic pressure is the same in all directions. The explosion propagates through the compound with a speed of three miles a second. Owing to all this, the whole mass will be converted into gas before the water can give way appreciably, and a spherical bubble 10 ft. in diameter will form. The gaseous pressure against the surrounding water will be 20,000 atmospheres, or 140 tons per square inch. When the great bubble has expanded to twice its original volume it will weigh as much as the water it displaces, and from that moment on, its lower end tapering more and more into a cone, it will be driven up with a rapidly-increasing force tending towards 20,000 tons. Under the terrific impulsion it would shoot up the surface like a bullet were it not for the water resistance, which will limit its maximum speed to 80 ft. per second.
Consider not the quantity and energy of the upheaval. The caloric potential energy of the compound is 2,800 heat units per pound, or, in mechanical equivalent, almost 1,000 ft.-tons. The entire potential energy of the explosive will thus be 66,000,000 ft.-tons. Of course, only a part of this immense store is transformable into mechanical effort. Theoretically, 40 lb. of good smokeless powder would be sufficient to impart to the Dreadnought's 850 lb. projectile the tremendous velocity mentioned above, but it actually takes a charge of 250 lb. The tidal wave generator is a dynamic transformer much superior to the gun, its greatest possible efficiency being as high as 44 per cent. Taking, to be conservative, 38 per cent, instead, there will be the total potential store about 25 million foot-tons obtained in mechanical energy.
HOW THE ENEMY WOULD BE ENGULFED.
Otherwise stated, 25,000,000 tons - that is, 860,000,000 cu. ft. of water, could be raised 1 ft., or a smaller quantity to a correspondingly greater elevation. The height and length of the wave will be determined by the depth at which the disturbance originated. Opening in the center like a volcano, the great hollows will belch forth a shower of ice. Some sixteen seconds later a valley of 600 ft. depth, counted from normal ocean level, will form, surrounded by a perfectly circular swell, approximately of equal height, which will enlarge in diameter at the rate of about 220 ft. per second.
It is futile to consider the effect of such an eruption on a vessel situated near by, however large. The entire navy of a great country, "if massed around, would be destroyed. But it is instructive to inquire what such a wave could do to a battleship of the Dreadnought type at considerable distance from it origin. A simple calculation will show that when the outer circle has expanded to three-quarters of a mile, the swell, about 1,250 ft. long, would still be more than 100 ft. in height, from crest to normal sea level, and when the circle is one and one-quarter mile in diameter the vertical distance from crest to trough will be over 100 ft.
The first impact of the water will produce pressures of three tons per square foot, which all over the exposed surface of, say, 20,000 sq. ft., may amount to 60.000 tons, eight times the force of the recoil of the broadside. That first impact may in itself be fatal. During more than ten seconds the vessel will be entirely submerged and finally dropped into the hollow from a height of about 75 ft., the descent being effected more or less like a free fall. It will then sink far below the surface, never to rise.