Stephen Gray

Beginnings

Gray is born with Canterbury in the Kent. After a brief education he becomes the apprentice of his father then of his older brother as dyer. However its interest goes on the Natural history, in particular on the Astronomie and he educates himself as an autodidact in these sciences émergeantes at that time. For this task it is mainly helped by easy friends in Kent which gives him access to their libraries and their scientific instruments. At that time science was mainly a rich person pastime.

The astronomer

He manufactures his clean lens S and a Télescope. With this instrument it makes a good number of minor discoveries, mainly in the field of the sunspots. It thus gains a good reputation for the precision of its observations. Some of its results are published by the Royal Society thanks to the mediation of a friend, Henry Hunt, which works with the secretariat of this Learned society.

This work draws the attention of John Flamsteed (which is dependant with friends of Gray of the Kent) the 1st royal astronomer which is building new the observatory of Greenwich. Flamsteed is creating a chart detailed and precise star S with the hope which it solves the problem of the determination of the Longitude for the sailors. Gray assistance with a good number of observations and calculations for which it was undoubtedly not paid.

Gray and Flamsteed become friends and correspond regularly and this seems to have creates problems with Gray in its meaning by the scientific world. Flamsteed then is engaged in an argument prolonged with Isaac Newton on the access to the preliminary data of the chart of Flamsteed. This quarrel turned in a war of factions inside the Royal Society in which Newton left victorious virtually excluding Flamsteed and its friends during several decades.

Gray works on the astronomical second Observatoire with Cambridge but it is so badly managed by the friends of Newton that the project fails not leaving an other alternative to Gray to only turn over to its trade of dyeing. However its health is problematic and soon it goes to London to assist Dr. John Theophilus Desaguliers, a member of Royal Society which gives readings in Great Britain and on the unintermitting to present the new scientific discoveries. Gray is probably not paid but receives the lodging and cover.

Poverty occurs for Gray. Thanks to the efforts of John Flamsteed and to sir Hans Sloane it obtains a pension with Charterhouse in London, a house for people desilvered having served Great Britain. At that time it begins its experiments on the static electricity by using a tube in Verre.

The discovery of conductivity

One night, in its room with Charterhouse, it notes that the Liege at the end of its tube protecting it from moisture and dust generates a gravitational attraction on small pieces of papers and bits of straws when the tube was rubbed. When it extends its experiment with a piece of wood planted in cork the load is obvious at the end of wood “with more strength than cork”. It tests with longer needles and finally adds a long wire finished by a ball in Ivoire. In this process he discovers that the virtue electricity can move and that the ivory ball attracts the light objects just like the tube out of glass.

Gray modifies its experiment to use metal wire in Fer and Cuivre like various materials: wood, plants green and dry, stone, teapot (vacuum, full with warm water, cool water) and discover that these materials them also lead the electric fluid. The following day he manages to transmit electricity up to 25 Mètre S (the height of the balcony of its room). All these tests until proceeded there vertically for probably practical reasons, it tests with horizontal but its first attempt fails. He concludes correctly that the electric fluid is dissipated by the supports of its assembly.

He then decides to try experiments on a greater height, a vertical assembly starting from the cupola of the Cathédrale Saint-Paul but before that he will see his friend Granville Wheler who has a large ideal house for his tests. After having carried out successfully several experiments Wheler suggests a horizontal assembly. Gray explains its failure to him. Wheler proposes to use wire of Soie to suspend conducting wire. Gray answers him “I says to him that would function better being given the smoothness of the support thus there would be less fluid escaping from the line of communication”. During same the few days he visits fortunate friends (close relations of Flamsteed) and with their assistance manages to extend his experiment on more than 250 meters.

Gray and Wheler discover the importance thus to isolate their assemblies from the ground by using silk. They also note that the transport of the electric fluid does not seem not facilitated by gravity while dropping the wire since a tower.

From these experiments are born a comprehension from the part played by the drivers and the insulators (name invented by John Theophilus Desaguliers). Charles DuFay, a French scientist, visits Gray and Wheler in 1732, sees the experiment, and after its return in France is the first to formulate a theory called theory of the two fluids . It is used by its associate the abbot Nollet and is opposed somewhat to that later of Benjamin Franklin and its group with Philadelphia. Franklin and the British experimenters Beavis and Watson study a theory using a fluid and two states that Watson names +ve and - ve which ends up prevailing on that of DuFay.

Gray continues to test, including the electric polarization of suspended objects; one often credits it with the experiment of the flying boy - a child suspended by silk wire and attracting bits of straws and other menus objects with his hands. He probably carried out years before Franklin that the flashes are due to the same phenomenon as the electric fluid.

Recognition

When Hans Sloane becomes president of the Royal Society, after the death of Isaac Newton, Gray receives the public recognition which was denied to him. It is the first to receive the Médaille Copley in 1731 for its work on the conductivity then in 1732 for those on the electrostatic Induction. The same year he is elected member of Royal Society.

It continues to work until on its bed of dead the February 15th 1736 or it describes with the doctor come to visit it work remaining to him to achieve.

Publications

The only known publications of Gray are addressed letters is with friends or Royal Society in which it describes some of its results. The majority of its letters are preserved nowadays in the files of Royal Society.

Its legacy

In spite of the importance of his work, for example one can argue that it is the first to include/understand the fact that an electric driver can transmit information, it received little credit during its life because of internal argument to the Royal Society. At the time or its discoveries are recognized publicly the experiments and the discoveries on the electricity are done at fast intervals and its discoveries seem commonplace. For this reason much of historians of sciences tended to be unaware of it.

There do not exist monuments and little recognition of its work. It is thought that it is buried in a common grave of an old London cemetery to a site reserved for the poor boarders of Charterhouse.

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