An earth battery is a pair of

electrode An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or a gas). In electrochemical cells, electrodes are essential parts that can consist of a varie ...

s made of two dissimilar metals, such as

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

and

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

, which are buried in the

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

or immersed in the

sea A sea is a large body of salt water. There are particular seas and the sea. The sea commonly refers to the ocean, the interconnected body of seawaters that spans most of Earth. Particular seas are either marginal seas, second-order section ...

. Earth batteries act as water-activated batteries. If the plates are sufficiently far apart, they can tap

telluric current Telluric (from the Latin ''tellus'', "earth") may refer to several things related to the Earth: * Telluric current, a natural electric current in the Earth's crust * Telluric contamination, contamination of astronomical spectra by the Earth's atmo ...

s . Earth batteries are sometimes referred to as telluric power sources and telluric generators.

History

One of the earliest examples of an earth battery was built by Alexander Bain in 1841 in order to drive a ''

prime mover Prime mover may refer to: Philosophy *Unmoved mover, a concept in Aristotle's writings Engineering * Prime mover (engine or motor), a machine that converts various other forms of energy (chemical, electrical, fluid pressure/flow, etc.) into ener ...

''—a device that transforms the flow or changes in pressure of a

fluid In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...

into

mechanical energy In physical sciences, mechanical energy is the sum of macroscopic potential and kinetic energies. The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical ...

. Bain buried plates of

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

and copper in the ground about one meter apart and used the resulting voltage, of about one volt, to operate a clock.

Carl Friedrich Gauss Johann Carl Friedrich Gauss (; ; ; 30 April 177723 February 1855) was a German mathematician, astronomer, geodesist, and physicist, who contributed to many fields in mathematics and science. He was director of the Göttingen Observatory and ...

, who had researched

Earth's magnetic field Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from structure of Earth, Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from ...

, and Carl August von Steinheil, who built one of the first electric clocks and developed the idea of an " Earth return" (or "ground return"), had previously investigated such devices. Daniel Drawbaugh received for an Earth battery for electric clocks (with several improvements in the art of Earth batteries). Another early patent was obtained by Emil Jahr ''Method of utilizing electrical Earth currents''). In 1875, James C. Bryan received for his ''Earth Battery''. In 1885, George Dieckmann, received US patent for his ''Electric Earth battery''. In 1898,

Nathan Stubblefield Nathan Beverly Stubblefield (November 22, 1860 – March 28, 1928) was an American inventor best known for his wireless telephone work. Self-described as a "practical farmer, fruit grower and electrician",

received for his electrolytic coil battery, which was a combination of an earth battery and a solenoid. (For more information see US patents , , , , , , and .) The Earth battery, in general, generated power for early telegraph transmissions and formed part of a

tuned circuit An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together. The circuit can act ...

that amplified the signalling voltage over long distances.

Operation and use

The simplest earth batteries consist of conductive plates from different metals of the electropotential series, buried in the ground so that the

acts as the

electrolyte An electrolyte is a substance that conducts electricity through the movement of ions, but not through the movement of electrons. This includes most soluble Salt (chemistry), salts, acids, and Base (chemistry), bases, dissolved in a polar solven ...

in a

voltaic cell A galvanic cell or voltaic cell, named after the scientists Luigi Galvani and Alessandro Volta, respectively, is an electrochemical cell in which an electric current is generated from spontaneous oxidation–reduction reactions. An example of a g ...

. As such, the device acts as a

primary cell A primary battery or primary cell is a battery (a galvanic cell) that is designed to be used once and discarded, and it is not rechargeable unlike a secondary cell ( rechargeable battery). In general, the electrochemical reaction occurring in ...

. When operated only as electrolytic devices, the devices were not continuously reliable, owing to drought condition. These devices were used by early experimenters as energy sources for

telegraphy Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pi ...

. However, in the process of installing long telegraph wires, engineers discovered that there were electrical potential differences between most pairs of telegraph stations, resulting from natural electrical currents (called

s) flowing through the ground. Some early experimenters did recognize that these currents were, in fact, partly responsible for extending the earth batteries' high outputs and long lifetimes. Later, experimenters would utilize these currents alone and, in these systems, the plates became polarized. It had been long known that continuous electric currents flowed through the solid and liquid portions of the Earth, and the collection of current from an electrically conductive medium in the absence of electrochemical changes (and in the absence of a thermoelectric junction) was established by Lord Kelvin.Method and apparatus for generating electricity, US Pat. 4153757. Column 1 Line 40 - Column 2 Line 4. Lord Kelvin's "sea battery" ''was not'' a chemical battery. Lord Kelvin observed that such variables as placement of the electrodes in the magnetic field and the direction of the medium's flow affected the current output of his device. Such variables do not affect battery operation. When metal plates are immersed in a liquid medium, energy can be obtained and generated, including (but not limited to) methods known via magneto-hydrodynamic generators. In the various experiments by Lord Kelvin, metal plates were symmetrically perpendicular to the direction of the medium's flow and were carefully placed with respect to a magnetic field, which differentially deflected electrons from the flowing stream. The electrodes can be asymmetrically oriented with respect to the source of energy, though. To obtain the natural electricity, experimenters would thrust two metal plates into the ground at a certain distance from each other in the direction of a magnetic meridian, or astronomical meridian. The stronger currents flow from south to north. This phenomenon possesses a considerable uniformity of current strength and voltage. As the Earth currents flow from south to north, electrodes are positioned, beginning in the south and ending in the north, to increase the voltage at as large a distance as possible.Bryan, James C., "U.S. Patent 160152 Earth Battery". February 23, 1875. p. 1, Column 1, Lines 29-32. In many early implementations, the cost was prohibitive because of an over-reliance on extreme spacing between electrodes. It has been found that all the common metals behave relatively similarly. The two spaced electrodes, having a load in an external circuit connected between them, are disposed in an electrical medium, and energy is imparted to the medium in such manner that "'' free electrons''" in the medium are excited. The free electrons then flow into one electrode to a greater degree than in the other electrode, thereby causing electric current to flow in the external circuit through the load. The current flows from that plate whose position in the electropotential series is near the negative end (such as

palladium Palladium is a chemical element; it has symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1802 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas (formally 2 Pallas), ...

). The current produced is highest when the two metals are most widely separated from each other in the electropotential series, and when the material nearer the positive end is to the north, while that at the negative end is towards the south. The plates, one copper and another iron or carbon, are connected above ground by means of a wire with as little resistance as possible. In such an arrangement, the electrodes are not appreciably chemically corroded, even when they are in earth saturated with water, and are connected together by a wire for a long time. It had been found that to strengthen the current, it was most advantageous to drive the northerly electropositive electrode deeper into the medium than the southerly electrode. The greatest currents and voltages were obtained when the difference in depth was such that a line joining the two electrodes was in the direction of the

magnetic dip Magnetic dip, dip angle, or magnetic inclination is the angle made with the horizontal by Earth's magnetic field, Earth's magnetic field lines. This angle varies at different points on Earth's surface. Positive values of inclination indicate t ...

, or magnetic inclination. When the previous methods were combined, the current was tapped and utilized in any well-known manner. In some cases, a pair of plates with differing electrical properties, and with suitable protective coatings, were buried below the ground. A protective or other coating covered each entire plate. A copper plate could be coated with powdered coke, a processed

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

aceous material. To a zinc plate, a layer of

felt Felt is a textile that is produced by matting, condensing, and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur, or from synthetic fibers such as petroleum-based acrylic fiber, acrylic or acrylonitrile or ...

could be applied. To use the natural electricity, earth batteries fed electromagnets, the load, that were part of a motor mechanism.

References and articles

General information

* Park Benjamin and Melvin L. Severy,
The Voltaic Cell: Its Construction and Its Capacity
'. Wiley, 1893. 562 pages. pp. 317–319. * George Milton Hopkins,
Experimental Science: Elementary, Practical and Experimental Physics
'. Munn & Co., 1902. pp. 437–451. * Frederick Collier Bakewell,
Electric science, its history, phenomena and applications
'. 1853. pp. 182–184. * James Napier,
A manual of electro-metallurgy
'. 1876. pp. 48–49. * William Edward Armytage Axon,
The Mechanic's Friend
'. Trübner, 1875. 339 pages. pp. 303–304. * Adolph A. Fesquet, Oliver Byrne, and John Percy,
The Practical Metal-worker's Assistant
'. H.C. Baird & Co., 1878. 683 pages. pp. 529–530. * Eugenii Katz, "

'". The history of electrochemistry, electricity and electronics; Biosensors & Bioelectronics. * Vassilatos, Gerry, "

'". * Burns, R. W., "
Alexander Bain, a most ingenious and meritorious inventor
'". Engineering Science and Education Journal, Volume 2, Issue 2, Apr 1993. pp. 85–93. ISSN 0963-7346 * R. J. Edwards G4FGQ
Measurement of Soil Resistivity & Calculation of Earth Electrode Resistance
. 15 February 1998 *
The Gentleman's magazine
'. (1731). London: .n. p. 587. * Spencer W. Richardson, "
The Flow of Electricity through Dielectrics
'". Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, Vol. 92, No. 635 (Nov. 1, 1915), pp. 101–107. * John Patterson Abernethy,
The Modern Service of Commercial and Railway Telegraphy
'. 1887. 423 pages. p. 72. * William Dwight,
Whitney Dictionary: An Encyclopedic Lexicon of the English Language
'. p. 1405. * Thomas Dixon Lockwood,
Electricity, Magnetism, and Electric Telegraphy
'. D. Van Nostrand Co., 1883. 375 pages. p. 42. ** * Edwin James Houston,
A Dictionary of Electrical Words, Terms and Phrases
'. P.F. Collier & Son, 1903. p. 756. * Henry Minchin,
Student's Text-book of Electricity
'. Lockwood, 1867. 519 pages. pp. 477–485.
Alternative copy
* Vassilatos, G. (2000). ''Lost science''. Kempton, Ill: Adventures Unlimited. * "
Telluric Currents: The Natural Environment and Interactions with Man-made Systems
'". The Earth's Electrical Environment (1986), Commission on Physical Sciences, Mathematics, and Applications. * Prescott, G. B. (1860).
History, theory, and practice of the electric telegram
'. Boston: Ticknor and Fields. 468 pages.

Citations and notes

Patents

* A. Bain, " ''Copying surfaces by electricity''". * A. Bain, " ''Improvements in electric telegraphs''". * W. P. Piggot, " ''Telegraph cable''". * W. D. Snow, " ''Earth-batteries for generating electricity''". * J. Cerpaux, " ''Electric piles''". * Daniel Drawbaugh, " ''Earth battery for electric clocks''". * M. Emme, " ''Ground generator of electricity''". * M. Emme, " ''Storage Battery''". * Jahr, Emil, " '' Method of utilizing electrical earth currents''". * Bryan, James C., " ''Improvements in lightning rods''". * Bryan, James C., " ''Earth Battery''". February 23, 1875. * Bryan, James C., " ''Improvements in lightning rods''". * James M. Dices, " ''Immersion type battery''". * Dieckmann, George F., " ''Electric Earth Battery''". November 3, 1885. * Stubblefield, Nathan, " ''Electric battery''". May 8, 1898. * William T. Clark, " ''Method and apparatus for generating electricity''". * Ryeczek, " ''Earth battery''". July 3, 1984.