Canterbury, Kent, England
|Died||7 February 1736 (aged 69)|
|Known for||Being the 'father' of electricity|
|Awards||Copley medal (1731, 1732)|
|Fields|| Chemistry |
|Institutions||Trinity College, Cambridge|
|Academic advisors|| Roger Cotes |
John Theophilus Desaguliers
Stephen Gray (December 1666 – 7 February 1736) was an English dyer and astronomer who was the first to systematically experiment with electrical conduction. Until his work in 1729 the emphasis had been on the simple generation of static charges and investigations of the static phenomena (electric shocks, plasma glows, etc.). He also first made the distinction between conduction and insulation, and discovered the action-at-a-distance phenomenon of electrostatic induction.
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the objective of achieving color with desired fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. Dye molecules are fixed to the fibre by absorption, diffusion, or bonding with temperature and time being key controlling factors. The bond between dye molecule and fibre may be strong or weak, depending on the dye used. Dyeing and printing are different applications; in printing color is applied to a localized area with desired patterns and in dyeing it is applied to the entire textile.
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets, and galaxies – in either observational or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. Related but distinct subjects like physical cosmology, which studies the Universe as a whole.
Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is named in contrast with current electricity, which flows through wires or other conductors and transmits energy.
Gray was born in Canterbury, Kent, and after some basic schooling, he was apprenticed to his father (and later his elder brother) in the cloth-dyeing trade. His interests lay with natural science and particularly with astronomy; he managed to educate himself in these developing disciplines, mainly through wealthy friends in the district, who gave him access to their libraries and scientific instruments. Science was very much a rich-man's hobby at this time.
He ground his own lenses and constructed his own telescope, and with this instrument he made a number of minor discoveries (mainly in the area of sunspots), gaining a reputation for accuracy in his observations. Some of his reports were published by the Royal Society through the agency of a friend, Henry Hunt, who was a member of the Society's secretarial staff.
The President, Council and Fellows of the Royal Society of London for Improving Natural Knowledge, commonly known as the Royal Society, is a learned society. Founded on 28 November 1660, it was granted a royal charter by King Charles II as "The Royal Society". It is the oldest national scientific institution in the world. The society is the United Kingdom's and Commonwealth of Nations' Academy of Sciences and fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, fostering international and global co-operation, education and public engagement.
Some of Gray's output came to the notice of John Flamsteed, a relative of some Kent friends of Gray and the first English Astronomer Royal, who was building the new Royal Greenwich Observatory. Flamsteed was attempting to construct a detailed and accurate star-map of the heavens, in the hope that this would eventually solve the problem of longitude determination for ocean navigators. Gray helped him with many of the observations and calculations (possibly without being paid).
John Flamsteed FRS was an English astronomer and the first Astronomer Royal. His main achievements were the preparation of a 3,000-star catalogue, Catalogus Britannicus, and a star atlas called Atlas Coelestis, both published posthumously. He also made the first recorded observations of Uranus, although he mistakenly catalogued it as a star, and he laid the foundation stone for the Royal Greenwich Observatory.
Astronomer Royal is a senior post in the Royal Households of the United Kingdom. There are two officers, the senior being the Astronomer Royal dating from 22 June 1675; the second is the Astronomer Royal for Scotland dating from 1834.
Gray and Flamsteed became constant correspondents and friends, and this seems to have created problems for Gray in being accepted formally into the world of science. Flamsteed was involved in a prolonged dispute with Sir Isaac Newton over access to preliminary star-chart data. This boiled over and became a factional war in the Royal Society, which Newton dominated (virtually excluding Flamsteed and his associates) for decades.
Sir Isaac Newton was an English mathematician, physicist, astronomer, theologian, and author who is widely recognised as one of the most influential scientists of all time, and a key figure in the scientific revolution. His book Philosophiæ Naturalis Principia Mathematica, first published in 1687, laid the foundations of classical mechanics. Newton also made seminal contributions to optics, and shares credit with Gottfried Wilhelm Leibniz for developing the infinitesimal calculus.
Gray worked for a while on the second English observatory, being built at Cambridge, but it was badly managed by Newton's friend and associate, Roger Cotes; the project finally collapsed, leaving Gray with little option but to return to his dyeing trade in Canterbury. Suffering from ill heallth, before long he was in London assisting John Theophilus Desaguliers, an acolyte of Isaac Newton and occasionally one of the Royal Society's demonstrators. Desaguliers acted as a scientific consultant, giving lectures around the country and on the Continent about new scientific discoveries; he also ran a boarding house for visiting gentlemen with scientific interests. Gray was not paid by Desaguliers, but provided with accommodation in exchange for his ability to discuss scientific subjects with the boarders.
Cambridge is a university city and the county town of Cambridgeshire, England, on the River Cam approximately 50 miles (80 km) north of London. At the United Kingdom Census 2011, its population was 123,867 including 24,506 students. Cambridge became an important trading centre during the Roman and Viking ages, and there is archaeological evidence of settlement in the area as early as the Bronze Age. The first town charters were granted in the 12th century, although modern city status was not officially conferred until 1951.
Roger Cotes FRS was an English mathematician, known for working closely with Isaac Newton by proofreading the second edition of his famous book, the Principia, before publication. He also invented the quadrature formulas known as Newton–Cotes formulas and first introduced what is known today as Euler's formula. He was the first Plumian Professor at Cambridge University from 1707 until his death.
John Theophilus Desaguliers FRS was a French-born British natural philosopher, clergyman, engineer and freemason who was elected to the Royal Society in 1714 as experimental assistant to Isaac Newton. He had studied at Oxford and later popularized Newtonian theories and their practical applications in public lectures. Desaguliers’s most important patron was James Brydges, 1st Duke of Chandos. As a Freemason, Desaguliers was instrumental in the success of the first Grand Lodge in London in the early 1720s and served as its third Grand Master.
Desaguliers' boarding house was demolished to make way for Westminster Bridge, and poverty intervened for Gray. In 1720, through the efforts of John Flamsteed and Sir Hans Sloane (later President of the Royal Society) he managed to obtain a pensioned position at the Charterhouse,a home for destitute gentlemen who had served their country, also linked to a boys' school. During this time he began experimenting with static electricity again, using a glass tube as a friction generator.
Westminster Bridge is a road-and-foot-traffic bridge over the River Thames in London, linking Westminster on the west side and Lambeth on the east side.
The London Charterhouse is a historic complex of buildings in Smithfield, London, dating back to the 14th century. It occupies land to the north of Charterhouse Square, and lies within the London Borough of Islington.
One night, in his Charterhouse rooms, he noticed that the cork at the end of his tube (needed to keep moisture and dust out) generated an attractive force on small pieces of paper and chaff when the tube was rubbed. Normally the cork would not have carried an electrical charge, but climatic conditions and variations in the materials meant that the cork was accumulating charge. When he extended the cork by inserting a small stick of fir, the charge manifested itself at the end of the stick, and then on an ivory ball (perforated with a hole) he had stuck on the end. he tried longer sticks, and finally added a length of an oily hemp pack-thread connected to the ivory ball. In the process he had discovered that the "electric virtue" was not just a 'static' phenomenon (like a local pin-prick), but rather a fluid-like substance that would carry over distance. The terminating ivory ball would still act to attract light objects in the same way as the electrified glass tube.
Over the next few days he extended the reach of his thread-wire (he only had a short piece of wire, and did not understand the significance of metal as a conductor) and found that it would carry from his balcony down into the courtyard below. He discovered that electricity would travel around bends in the thread and that it appeared unaffected by gravity. He was also able to transmit charges to metal objects (poker, tongs, kettle, etc.) which were generally regarded in those days as 'non-electrics' because they couldn't generate or hold static charge. He also discovered that silk would not carry the 'virtue', while the thicker pack-thread and wire could.
Then between 30 June and 2 July 1729 while in Kent he extended this first electrical network and made many new discoveries. On a visit to the Reverend Granville Wheler, a wealthy friend, member of the Royal Society and Famsteed's relative, the two men extended the conduction experiments through pack-thread laced up and down the length of a large gallery in Wheler's manor house, Otterden Place in Kent. In the process, Gray and Wheler discovered the importance of insulating their thread 'conductor' from earth contact (the wall of the house) by using silk for suspension. They noticed that if wire was used to support the pack-thread, all the 'electrical virtue' leaked away. Initially they thought the difference was due to the relative thicknesses of the silk, thread and wire, but later they realised that silk itself was much less conducting than the wire—so they used only silk to support (and thereby insulate) the hemp pack-thread used as their main conductor.
The next day they dropped the thread from the house tower to the garden and then extended it out across a paddock to a distance of 800 feet using paired garden-stakes with short spans of silk to keep the pack-thread from touching the ground. 242–247 Wheler reported this to many of his Royal Society friends, and Gray wrote the full details in a letter to Desaguliers.:
From these experiments came an understanding of the role played by conductors and insulators (names applied by Desaguliers). Two French scientists, Abbe Nollet and C.F. du Fay, visited Gray and Wheler in 1732, saw the experiment, and returned to France where du Fay formulated the first comprehensive theory of electricity called the "two-fluid" theory. This theory was championed by Nollet and accepted by most experimenters in Europe for a time; later it was refined and then superseded by the ideas of the English experimenters John Bevis and William Watson, who were in correspondence with Benjamin Franklin's group in Philadelphia. They jointly devised a theory of a single-fluid/two-state: virtually, the super-abundance or absence of one fluid, which Watson later termed positive and negative. These ideas fitted the facts slightly better than the two-fluid concept, especially after the invention of the Leyden Jar, and this single-fluid theory eventually prevailed. We now know that both were almost equally incorrect.
Gray went on to make more electrical discoveries, the most noticeable being electrical induction (creating an electrical charge in a suspended object without contact). This experiment was widely celebrated around Europe as the famous "Flying Boy" demonstration: a boy was suspended on silk cords, and then charged by Gray bringing his rubbed tube (static electric generator) close to the boy's feet, but without touching. Gray showed that the boy's face and hands still attracted the chaff, paper and other materials.Gray certainly realised that the phenomenon of 'electric virtue' was the same as lightning (as did most experimenters), many years before Franklin "flew his kite" and the French experimenters Dilibard and Delor captured a charge from lightning in a Leyden Jar.
When Sloane took over the Royal Society on Newton's death, Gray belatedly received the recognition denied him previously. Gray was too poor to pay the dues, so he was not a member of the Royal Society, and many of his experiments had been taken up and became part of the demonstration repertoire of Desaguliers. There is also a story that he was denied recognition by the Newton faction within the Royal Society because of his links to Flamsteed (who was constantly in dispute with Isaac Newton), but this can be dismissed as highly unlikely: Newton had died in March 1727, nearly two years before Gray began his conduction experiments, and Hans Sloan, who ran the Royal Society after Newton's death was a friend and financial supporter of Gray. The fact is that electricity was not considered that important at the time, and the Society's magazine was not published for a couple of years due to financial constraints.
Sloan took an active part in promoting Gray, who received the Royal Society's first Copley Medal in 1731 for his work on conduction and insulation, and also its second in 1732 for his induction experiments. In 1732 the Royal Society also admitted him as an honorary member; he died destitute a few years later, in 1736.
Despite the importance of his discoveries (it can be argued that he was the inventor of electrical communications), he received little credit, supposedly because of the factional dispute in the Royal Society, and the dominance of Newtonianism. Desaguliers achieved far more fame than Gray, and many of Gray's discoveries became attached to the name Desaguliers by virtue of his flamboyant demonstrations. By the time Gray's priority was publicly recognised, experiments in electricity had moved on and people were interested more in the spectacular feats by Franklin and others in capturing lightning in their Leyden Jars. Gray's discoveries tended to look trivial, and for this reason some historians tend to overlook his work.
There is no monument to Gray, and little recognition of what he achieved in his scientific discoveries. He is believed to be buried in a common grave in an old London cemetery, in an area reserved for pauper pensioners from the Charterhouse. In 2017 the School of Physical Sciences at the University of Kent, in Canterbury, initiated the Stephen Gray Lectures in his memory.
Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charges; positive and negative. Like charges repel and unlike attract. An object with an absence of net charge is referred to as neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects.
Timeline of electromagnetism and classical optics lists, within the history of electromagnetism, the associated theories, technology, and events.
Luigi Aloisio Galvani was an Italian physician, physicist, biologist and philosopher, who discovered animal electricity. He is recognized as the pioneer of bioelectromagnetics. In 1780, he discovered that the muscles of dead frogs' legs twitched when struck by an electrical spark. This was one of the first forays into the study of bioelectricity, a field that still studies the electrical patterns and signals from tissues such as the nerves and muscles.
An electroscope is an early scientific instrument used to detect the presence of electric charge on a body. It detects charge by the movement of a test object due to the Coulomb electrostatic force on it. The amount of charge on an object is proportional to its voltage. The accumulation of enough charge to detect with an electroscope requires hundreds or thousands of volts, so electroscopes are used with high voltage sources such as static electricity and electrostatic machines. An electroscope can only give a rough indication of the quantity of charge; an instrument that measures electric charge quantitatively is called an electrometer.
Jean Charles Athanase Peltier was a French physicist. He was originally a watch dealer, but at 30 years old took up experiments and observations in physics.
Sir William Watson, FRS was an English physician and scientist who was born and died in London. His early work was in botany, and he helped to introduce the work of Carolus Linnaeus into England. He became a Fellow of the Royal Society in 1741 and vice president in 1772.
Fluid theories of electricity are outdated theories that postulated one or more electrical fluids which were thought to be responsible for many electrical phenomena in the history of electromagnetism. The "two-fluid" theory of electricity, created by Charles François de Cisternay du Fay, postulated that electricity was the interaction between two electrical 'fluids.' An alternate simpler theory was proposed by Benjamin Franklin, called the unitary, or one-fluid, theory of electricity. This theory claimed that electricity was really one fluid, which could be present in excess, or absent from a body, thus explaining its electrical charge. Franklin’s theory explained how charges could be dispelled and how they could be passed through a chain of people. The fluid theories of electricity eventually became updated to include the effects of magnetism, and electrons.
Francis Hauksbee the Elder FRS (1660–1713), also known as Francis Hawksbee, was an 18th-century English scientist best known for his work on electricity and electrostatic repulsion.
Electrochemistry, a branch of chemistry, went through several changes during its evolution from early principles related to magnets in the early 16th and 17th centuries, to complex theories involving conductivity, electric charge and mathematical methods. The term electrochemistry was used to describe electrical phenomena in the late 19th and 20th centuries. In recent decades, electrochemistry has become an area of current research, including research in batteries and fuel cells, preventing corrosion of metals, the use of electrochemical cells to remove refractory organics and similar contaminants in wastewater electrocoagulation and improving techniques in refining chemicals with electrolysis and electrophoresis.
The history of electromagnetic theory begins with ancient measures to understand atmospheric electricity, in particular lightning. People then had little understanding of electricity, and were unable to explain the phenomena. Scientific understanding into the nature of electricity grew throughout the eighteenth and nineteenth centuries through the work of researchers such as Ampère, Coulomb, Faraday and Maxwell.
Otterden is a civil parish and village on the Kent Downs in the borough of Maidstone in Kent, England.
Pierre Polinière was an early investigator of electricity and electrical phenomena, notably "barometric light", a form of gas-discharge light, which suggested the possibility of electric lighting. He also helped to introduce the scientific method in French universities.
Granville Wheler was an English clergyman and scientist.
Robert Symmer, FRS (1707–1763) was a Scottish philosopher and physicist, known principally for the now defunct fluid theory of electricity.
Lieutenant-General Thomas Desaguliers was a British Army general and a Colonel Commandant of the Royal Artillery.
Experiments and Observations on Electricity is a mid-eighteenth century book consisting of letters from Benjamin Franklin. These letters concerned Franklin's discoveries about the behavior of electricity based on experimentation and scientific studies. The book came in pamphlet form for the first three English editions. The last two editions were in a book volume with hard covers and a book spine. There were eleven European editions of the book: five English editions, three French editions, and a German, Italian and Latin edition. The publication was well received worldwide. It was considered America's most important scientific book of the eighteenth century.
Franklin's electrostatic machine is a high-voltage static electricity-generating device used by Benjamin Franklin in the mid-18th century for research into electrical phenomena. Its key components are a glass globe which turned on an axis via a crank, a cloth pad in contact with the spinning globe, a set of metal needles to conduct away the charge developed on the globe by its friction with the pad, and a Leyden jar – a high-voltage capacitor – to accumulate the charge. Franklin's experiments with the machine eventually led to new theories about electricity and inventing the lightning rod.
Not to be confused with the unrelated Georg Bose.