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Stephen Gray (December 1666 – 7 February 1736) was an English dyer and
astronomer 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 ...
who was the first to systematically experiment with
electrical conduction Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...
. Until his work in 1729 the emphasis had been on the simple generation of
static Static may refer to: Places *Static Nunatak, a nunatak in Antarctica United States * Static, Kentucky and Tennessee * Static Peak, a mountain in Wyoming ** Static Peak Divide, a mountain pass near the peak Science and technology Physics *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 Electrostatic induction, also known as "electrostatic influence" or simply "influence" in Europe and Latin America, is a redistribution of electric charge in an object that is caused by the influence of nearby charges. In the presence of a char ...
.


Early life

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 The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
through the agency of a friend, Henry Hunt, who was a member of the Society's secretarial staff.


Introduction to Flamsteed

Some of Gray's output came to the notice of
John Flamsteed John Flamsteed (19 August 1646 – 31 December 1719) 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 Co ...
, a relative of some Kent friends of Gray and the first English
Astronomer Royal 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 junior is the Astronomer Royal for Scotland dating from 1834. The post ...
, who was building the new
Royal Greenwich Observatory The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in ...
. 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). 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 Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a "natural philosopher"), widely recognised as one of the great ...
over access to preliminary star-chart data. This boiled over and became a factional war in the
Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
, which Newton dominated (virtually excluding Flamsteed and his associates) for decades. Gray worked for a while on the second English observatory, being built at
Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge beca ...
, but it was badly managed by Newton's friend and associate,
Roger Cotes Roger Cotes (10 July 1682 – 5 June 1716) 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 quadrat ...
; the project finally collapsed, leaving Gray with little option but to return to his dyeing trade in Canterbury. Suffering from ill health, before long he was in London assisting
John Theophilus Desaguliers John Theophilus Desaguliers FRS (12 March 1683 – 29 February 1744) was a 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 O ...
, 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. Desaguliers' boarding house was demolished to make way for
Westminster Bridge 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 bridge is painted predominantly green, the same colour as the leather seats in the H ...
, and poverty intervened for Gray. In 1720, through the efforts of John Flamsteed and
Sir Hans Sloane Sir Hans Sloane, 1st Baronet (16 April 1660 – 11 January 1753), was an Irish physician, naturalist, and collector, with a collection of 71,000 items which he bequeathed to the British nation, thus providing the foundation of the British Mu ...
(later President of the Royal Society) he managed to obtain a pensioned position at the
Charterhouse Charterhouse may refer to: * Charterhouse (monastery), of the Carthusian religious order Charterhouse may also refer to: Places * The Charterhouse, Coventry, a former monastery * Charterhouse School, an English public school in Surrey London ...
, 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.


Conduction discoveries

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 a 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 Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it fac ...
. 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 a 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. 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 Jean-Antoine Nollet (; 19 November 170025 April 1770) was a French clergyman and physicist who did a number of experiments with electricity and discovered osmosis. As a deacon in the Catholic Church, he was also known as Abbé Nollet. Biography ...
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 William, Willie, Bill or Billy Watson may refer to: Entertainment * William Watson (songwriter) (1794–1840), English concert hall singer and songwriter * William Watson (poet) (1858–1935), English poet * Billy Watson (actor) (1923–2022), A ...
, who was in correspondence with
Benjamin Franklin Benjamin Franklin ( April 17, 1790) was an American polymath who was active as a writer, scientist, inventor, statesman, diplomat, printer, publisher, and political philosopher. Encyclopædia Britannica, Wood, 2021 Among the leading inte ...
's group in
Philadelphia Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sin ...
. 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 A Leyden jar (or Leiden jar, or archaically, sometimes Kleistian jar) is an electrical component that stores a high-voltage electric charge (from an external source) between electrical conductors on the inside and outside of a glass jar. It typ ...
, and this single-fluid theory eventually prevailed. We now know that both were almost equally incorrect.


And electrostatic induction, and belated recognition

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 The Copley Medal is an award given by the Royal Society, for "outstanding achievements in research in any branch of science". It alternates between the physical sciences or mathematics and the biological sciences. Given every year, the medal is ...
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.


After his death

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 The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
, and the dominance of Newtonianism. 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 Charterhouse may refer to: * Charterhouse (monastery), of the Carthusian religious order Charterhouse may also refer to: Places * The Charterhouse, Coventry, a former monastery * Charterhouse School, an English public school in Surrey London ...
. In 2017 the School of Physical Sciences at the
University of Kent , motto_lang = , mottoeng = Literal translation: 'Whom to serve is to reign'(Book of Common Prayer translation: 'whose service is perfect freedom')Graham Martin, ''From Vision to Reality: the Making of the University of Kent at Canterbury'' ...
, in Canterbury, initiated the Stephen Gray Lectures in his memory."Stephen Gray Lectures ", School of Physical Sciences at Kent blog, https://blogs.kent.ac.uk/spskent/stephen-gray-lectures/ (accessed 4 July 2018).


References


Further reading

*David H. Clark & Stephen H.P. Clark, ''Newton's Tyranny: The Suppressed Scientific Discoveries of Stephen Gray and John Flamsteed'', W. H. Freeman, 2001 Reviewed in ; . * * * * * * Stephen Williamson (2022) "New light on Stephen Gray, FRS (1666-1736), Canterbury freeman dyer." ''Archaeologia Cantiana.'' CXLIII: 292-304. *


External links


Gray at Britannica online


{{DEFAULTSORT:Gray, Stephen 1666 births 1736 deaths Fellows of the Royal Society 18th-century British physicists People from Canterbury Recipients of the Copley Medal 17th-century English astronomers 18th-century British astronomers People associated with electricity