Louis François Clément Breguet (22 December 1804 – 27 October 1883), was a French physicist and watchmaker, noted for his work in the early days of

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 p ...

. Educated in Switzerland, Breguet was the grandson of

Abraham-Louis Breguet Abraham-Louis Breguet (10 January 1747 – 17 September 1823), born in Neuchâtel, then a Prussian principality, was a horologist who made many innovations in the course of a career in watchmaking industry. He was the founder of the Bregue ...

, founder of the watch manufacturing company Breguet. He became manager of ''Breguet et Fils'' watchmakers in 1833 after his father Louis Antoine Breguet retired. Between 1835 and 1840 he standardized the company product line of watches, then making 350 watches per year, and diversified into scientific instruments, electrical devices, recording instruments, an electric thermometer, telegraph instruments and electrically synchronized clocks. With Alphonse Foy, in 1842 he developed the Foy-Breguet telegraph, an electrical

needle telegraph A needle telegraph is an electrical telegraph that uses indicating needles moved electromagnetically as its means of displaying messages. It is one of the two main types of electromagnetic telegraph, the other being the armature system, as exem ...

to replace the

optical telegraph An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals. There are two main types of such systems; the semaphore telegraph which uses pivoted indicator arms and ...

system then in use. and a later step-by-step telegraph system (1847) was applied to French railways and exported to Japan. He observed in 1847 that small wires could be used to protect telegraph installations from

lightning Lightning is a naturally occurring electrostatic discharge during which two electric charge, electrically charged regions, both in the atmosphere or with one on the land, ground, temporarily neutralize themselves, causing the instantaneous ...

, the ancestor of the

fuse Fuse or FUSE may refer to: Devices * Fuse (electrical), a device used in electrical systems to protect against excessive current ** Fuse (automotive), a class of fuses for vehicles * Fuse (hydraulic), a device used in hydraulic systems to protect ...

. He also manufactured the rotating mirror

Fizeau–Foucault apparatus The Fizeau–Foucault apparatus is either of two types of instrument historically used to measure the speed of light. The conflation of the two instrument types arises in part because Hippolyte Fizeau and Léon Foucault had originally been friends ...

, used by

Léon Foucault Jean Bernard Léon Foucault (, ; ; 18 September 1819 – 11 February 1868) was a French physicist best known for his demonstration of the Foucault pendulum, a device demonstrating the effect of Earth's rotation. He also made an early measurement ...

and

Hippolyte Fizeau Armand Hippolyte Louis Fizeau FRS FRSE MIF (; 23 September 181918 September 1896) was a French physicist, best known for measuring the speed of light in the namesake Fizeau experiment. Biography Fizeau was born in Paris to Louis and Beatrice Fiz ...

to measure the

speed of light The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit ...

(1850). In 1856 he designed a public network of synchronized electric clocks for the center of Lyon. In 1866 he patented an electric clock controlled by a 100 Hz tuning fork. In 1870 he transferred the leadership of the

company A company, abbreviated as co., is a Legal personality, legal entity representing an association of people, whether Natural person, natural, Legal person, legal or a mixture of both, with a specific objective. Company members share a common p ...

to Edward Brown. Breguet then focused entirely on the telegraph and the nascent field of telecommunications. He collaborated in the development of an

induction coil An induction coil or "spark coil" (archaically known as an inductorium or Ruhmkorff coil after Heinrich Rühmkorff) is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current (DC) supply. p.98 To ...

, later improved by

Heinrich Ruhmkorff Heinrich Daniel Ruhmkorff (Rühmkorff) (15 January 1803 – 20 December 1877) was a German instrument maker who commercialised the induction coil (often referred to as the Ruhmkorff coil). Ruhmkorff was born in Hanover. He changed the "ü" ...

. In terms of honors, in 1843 he was appointed to the Bureau of Longitudes. In 1845 Breguet was awarded the

Legion d'Honneur The National Order of the Legion of Honour (french: Ordre national de la Légion d'honneur), formerly the Royal Order of the Legion of Honour ('), is the highest French order of merit, both military and civil. Established in 1802 by Napoleon B ...

. He was made a member of the

French Academy of Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific me ...

in 1874, and was elevated to Officer of the Legion d'Honneur in 1877. He is one of the 72 French scientists whose names are written around the base of the

Eiffel Tower The Eiffel Tower ( ; french: links=yes, tour Eiffel ) is a wrought-iron lattice tower on the Champ de Mars in Paris, France. It is named after the engineer Gustave Eiffel, whose company designed and built the tower. Locally nicknamed "'' ...

. Breguet was married and had one son Antoine (1851–1882) who also joined the family electrical business. With his son, he met

Alexander Graham Bell Alexander Graham Bell (, born Alexander Bell; March 3, 1847 – August 2, 1922) was a Scottish-born inventor, scientist and engineer who is credited with patenting the first practical telephone. He also co-founded the American Telephone and Te ...

and obtained a license to manufacture Bell telephones for the French market.Anton A. Huurdeman ''The worldwide history of telecommunications'' page 168 He was the grandfather of

Louis Charles Breguet Louis Charles Breguet (2 January 1880 in Paris – 4 May 1955 in Saint-Germain-en-Laye, Île-de-France) was a French aircraft designer and builder, one of the early aviation pioneers. Biography Louis Charles Breguet was the grandson of Lo ...

and the uncle of Sophie Berthelot.

References

{{DEFAULTSORT:Breguet, Louis Francois Clement Members of the French Academy of Sciences 1804 births 1883 deaths French physicists French watchmakers (people) Officiers of the Légion d'honneur French scientific instrument makers Burials at Père Lachaise Cemetery