Rota's Two 1919 British Patents: Wave Concentration and the Telluric Mine Detector

Luigi Giovanni Valerio Rota was an Italian-born inventor who worked in Britain and France in the early twentieth century, and who is remembered chiefly for a family of claims about earth-borne "universal currents." Two British complete specifications accepted in the summer of 1919 set out the technical core of that program: one describes an apparatus for concentrating electric waves on a chosen point, and the other describes a ship-borne instrument for detecting mines, submarines, ships and icebergs by sensing what Rota called telluric magnetic vortices. The two documents are distinct inventions with different named inventors, different filing dates and different subject matter, and they should be read separately even though they arrived in the same dossier.

The wave-concentration patent

The earlier application, filed on 14 August 1917 and accepted on 3 July 1919, is credited to Rota together with Ernesto Binetti of Rome, described as a commendatore. Its stated objects are a list of radio-engineering ambitions: to concentrate a wave or train of waves on a desired point; to guarantee that a station communicates only with its appointed correspondent, without interception or interference; to let several stations operate close together without mutual disturbance; to suppress the dissipations and absorptions that waves suffer from atmospheric electricity; to allow ordinary omnidirectional working when the apparatus is switched out of circuit; to increase capacity and to fix the phase and intensity of the wave, so that electric power might be transmitted wirelessly at a distance, for instance to produce a Joule effect remotely; and to transmit a wave whose constitution reveals when a magnetic body has come between transmitter and receiver, whether on land, on water or under water.

The mechanism is described as a set of two, three or more cylinders joined in series through reciprocal induction. Each cylinder is connected to a common battery, accumulator or dynamo, but the polarity applied to alternate cylinders is reversed. Working on the principle of transformers, the arrangement is said to let the first stage raise intensity, the second raise electromotive force, and the third equalize the two, or to reverse that ordering as needed, so that energy, intensity, electromotive force and period are all brought into relation. The battery is assigned the further role of reconstituting losses from resistance and other passive causes and of restoring to the wave what the specification calls its constitutive and primitive property. The cylinders are also said to increase capacity and reduce resistance.

The specification is deliberately permissive about construction. The cylinders may be single or double, mounted horizontally, vertically or inclined, and may have circular, square, rectangular, triangular or other cross-sections; they may be built from sheet metal or from parallel wires or bands, depending on the station and the service. The text notes that the system may be directly coupled or use damped or undamped waves, and that the underlying basis and action of the apparatus remain the same while details vary.

The mine- and ship-detection patent

The second specification, filed on 28 May 1918 and accepted on 30 June 1919, names Rota alone, then of 55 Eardley Crescent, Earl's Court, London, as professor. Its object is to signal the presence and direction of floating mines, submarines and other ships, other magnetic or paramagnetic bodies, and icebergs, whether floating or submerged, and to indicate their speed from the change in indicated direction.

The operating principle is stated as a discovery: certain telluric or earth currents produce telluric magnetic vortices in the earth, and the presence or intensity of these currents becomes observable when they encounter a magnetic or paramagnetic body, however small. On that basis the apparatus is claimed to reveal a mine, submarine or ship by indicating the currents themselves.

The drawings show a vertical longitudinal section with some parts in elevation, a horizontal section through the axis, a transverse section on the line 3–3 of the second figure, and an axial section of a modification. The main body is a wooden cylinder or casing, hermetically closed, which may be enclosed in a pointed outer iron casing when the device is meant for use in water, where the casing reduces resistance and withstands water pressure. The cylinder is carried by rods fixed to a vertical shaft that runs in a ball bearing on a vertical rod; that rod may be telescopic and locked by a set screw. The upper ball bearing lets the apparatus turn about a vertical axis, and a further ball bearing on an arm fixed to the ship lets the shaft and rod hang vertically. The specification notes that any suspension may be used that keeps the longitudinal axis horizontal, allows orientation about a central vertical axis, and permits raising and lowering, and that the device may hang at the bows or the side of a ship.

Inside the casing, concentric with it, sits a rotating wooden cylinder carried on radial arms or spokes that run on ball bearings on a rod fixed to the casing. It may be driven by clockwork housed at one end of the casing; the drawings show a bevel wheel on the cylinder's end driven by a bevel pinion on a flexible shaft that would run up to the deck and be driven there. The specification states explicitly that an electric motor cannot be used at that end of the casing because it would prevent accurate observations. The rotating cylinder is given a surface velocity of 4 to 9 metres per second.

Insulated copper or soft-iron wire is wound on the rotating cylinder in one or more layers to form a closed circuit. The ends of that circuit carry brushes or contacts that ride on rings connected to a very sensitive galvanometer. A fixed frame, shown rectangular but allowed to be cylindrical or polygonal, sits partly inside the rotating cylinder, concentric with it, and carries coils of soft-iron wire or thin plates forming a closed circuit. Inside the frame, parallel to a plane of a convolution of the wires or plates, is a magnetic declination needle, positioned so that the wires or plates point north. A mirror is fixed above the needle, and the needle is read by reflection in mirrors while the galvanometer is read directly through a tube that may carry lenses, with a lamp for illumination.

Two operating modes are given. In one, the cylinder is stationary with its axis at right angles to the magnetic meridian; in the other, the cylinder rotates with its axis parallel to the meridian or inclined to it at 30 to 35 degrees. Two such devices may be used together, one with a stationary cylinder and one with a rotating cylinder, and one of them may carry a dip needle.

A modification is described for detecting an iceberg, which the specification attributes to the iceberg's high electric potential. In that version the outer casing is omitted and two copper cylinders are provided, one inside and one outside the wooden cylinder, each extending roughly half its length and carried by a disk closing the end of the rotating cylinder; the copper cylinders are connected to an electroscope or a torsion balance.

The Marseilles press account

The dossier also carries a press report describing a preliminary demonstration at Marseilles. According to that account, Rota showed a cigar-shaped apparatus seventeen feet long, thirty inches in diameter and weighing 200 pounds, and persuaded a number of press correspondents that it could remain suspended motionless in the air for twenty-four hours while carrying a considerable weight, and could be propelled or stopped without any mechanical motor. The same report attributes to Rota the prediction that a new power would first make coal, steam, oil and electricity more efficient and afterward dispense with them altogether, and that spectacular demonstrations would follow once a company was formed. It also records that the reality of telluric currents had been suspected by other scientists, that Lord Kelvin had affirmed their existence before his death, and that Rota claimed to be the first to discover and record them, describing them as a "molecular force" distinct from Ampère's thermo-electric currents and from Foucault currents.

This account is a newspaper-style report of a demonstration, not an instrumented measurement, and it should be read as a claim made to journalists rather than as a verified result. The patent specifications themselves contain no flight or suspension data.

Biographical framing

A short biographical section by Mike Watson places Rota as a Frenchman of Italian origin, born in 1886 and died at Genesieux near Valence in France in 1951. It notes that his early life is little documented, that he was involved in early aviation and in experiments in wireless communication and anti-gravitation, that he came from northern Italy and was a contemporary of Marconi and almost certainly influenced by him, and that he wrote little about his claimed discovery of the Universal Current, producing two short booklets based on seminars, one in collaboration with a medical doctor named Kresser.

Evidence and open questions

Both documents are granted patent specifications. A grant establishes that the application met the formal requirements of the patent office; it does not establish that the described apparatus works as claimed. The detection principle in the second patent is presented as the inventor's discovery rather than as a demonstrated effect, and the iceberg modification invokes a high electric potential without explaining the mechanism by which it would be sensed. The wave-concentration patent's claims about wireless power transmission and about restoring a wave's "primitive property" are assertions within the inventor's own framework.

One bibliographic oddity is worth recording. The dossier is headed with the number of the detection patent, but its opening text block is the specification of the wave-concentration patent, and the two specifications are interleaved through the file. The two inventions must therefore be kept apart when citing the dossier: the cylinder-series wave concentrator belongs to the 1917 application, and the suspended rotating-cylinder detector belongs to the 1918 application.

Related work

The two patents extend the Rota dossier already represented in this wiki by Louis Rota, GB128624A: Rota and Binetti's Apparatus for Concentrating Electric Waves and Rota's Two 1919 British Patents: Wave Concentration and the Telluric Mine Detector, and they supply the full detection specification behind concepts/telluric-magnetic-vortex-claim and concepts/universal-currents-claim. The press account of a suspended cigar-shaped craft connects to concepts/electrogravitation-claim-rota and entities/fr508472, while the detection apparatus relates to the ground-radio and detector material in concepts/ground-radio and concepts/neon-detector. Earlier Rota source articles in this wiki include and .