he+is+recording+in+paris

SUBJECT AREA: Medical technology, Photography, film and optics

[br]

[br]

[br]

At the age of 19 Marey went to Paris to study medicine, becoming particularly interested in the problems of the circulation of the blood. In an early communication to the Académie des Sciences he described a much improved device for recording the pulse, the sphygmograph, in which the beats were recorded on a smoked plate. Most of his subsequent work was concerned with methods of recording movement: to study the movement of the horse, he used pneumatic sensors on each hoof to record traces on a smoked drum; this device became known as the Marey recording tambour. His attempts to study the wing movements of a bird in flight in the same way met with limited success since the recording system interfered with free movement. Reading in 1878 of Muybridge's work in America using sequence photography to study animal movement, Marey considered the use of photography himself. In 1882 he developed an idea first used by the astronomer Janssen: a camera in which a series of exposures could be made on a circular photographic plate. Marey's "photographic gun" was rifle shaped and could expose twelve pictures in approximately one second on a circular plate. With this device he was able to study wing movements of birds in free flight. The camera was limited in that it could record only a small number of images, and in the summer of 1882 he developed a new camera, when the French government gave him a grant to set up a physiological research station on land provided by the Parisian authorities near the Porte d'Auteuil. The new design used a fixed plate, on which a series of images were recorded through a rotating shutter. Looking rather like the results provided by a modern stroboscope flash device, the images were partially superimposed if the subject was slow moving, or separated if it was fast. His human subjects were dressed all in white and moved against a black background. An alternative was to dress the subject in black, with highly reflective strips and points along limbs and at joints, to produce a graphic record of the relationships of the parts of the body during action. A one-second-sweep timing clock was included in the scene to enable the precise interval between exposures to be assessed. The fixed-plate cameras were used with considerable success, but the number of individual records on each plate was still limited. With the appearance of Eastman's Kodak roll-film camera in France in September 1888, Marey designed a new camera to use the long rolls of paper film. He described the new apparatus to the Académie des Sciences on 8 October 1888, and three weeks later showed a band of images taken with it at the rate of 20 per second. This camera and its subsequent improvements were the first true cinematographic cameras. The arrival of Eastman's celluloid film late in 1889 made Marey's camera even more practical, and for over a decade the Physiological Research Station made hundreds of sequence studies of animals and humans in motion, at rates of up to 100 pictures per second. Marey pioneered the scientific study of movement using film cameras, introducing techniques of time-lapse, frame-by-frame and slow-motion analysis, macro-and micro-cinematography, superimposed timing clocks, studies of airflow using smoke streams, and other methods still in use in the 1990s. Appointed Professor of Natural History at the Collège de France in 1870, he headed the Institut Marey founded in 1898 to continue these studies. After Marey's death in 1904, the research continued under the direction of his associate Lucien Bull, who developed many new techniques, notably ultra-high-speed cinematography.

[br]

See also: Demenÿ, Georges

BC / MG

1 study.

ha dedicado muchos años al estudio del tema she has studied the subject for many years

estar en estudio to be under consideration

estudio de campo field study

estudio de mercado market research; (técnica) market survey (investigación)

estudio de viabilidad feasibility study

2 study (oficina).

3 studio (Cine, Rad & TV).

los estudios de la Metro the Metro studios

estudio cinematográfico film studio

estudio de grabación recording studio

1^st person singular (yo) present indicative of spanish verb: estudiar.

* * *

► nombre masculino

1 (gen) study

2 (encuesta) survey, study; (investigación) research

3 (apartamento) studio flat (US apartment), bedsit

4 (sala) studio

► nombre masculino plural estudios

1 (conocimientos) studies, education sing

\

cursar estudios to study

dar estudios a alguien to pay for somebody's education

dedicarse al estudio de algo to study something

estar algo en estudio to be under consideration

hacer estudios to study

tener estudios to be well-educated

estudio cinematográfico film studio

estudio de grabación recording studio

estudio de mercado market research

estudio de televisión television studio

* * *

1) study

2) studio

3) den

* * *

1) (=investigación) study

2) (=actividad investigadora) study

3) (=análisis) [de intención de voto, edificio] survey

4) pl estudios (=educación) education sing

5) (=erudición) learning

6) (Arte, Mús) study

7) (=lugar de trabajo)

a) [en una casa] study

b) [profesional] [de artista, arquitecto] studio; Cono Sur [de abogado] office

c) (Cine, Radio, TV) studio

8) (=apartamento) studio, studio flat

* * *

1)

a) (Educ) ( actividad)

b) (investigación, análisis) study

c) (de asunto, caso) consideration

- estudio de mercado

2) ( lugar)

a) ( de artista) studio; ( de arquitecto) office, studio; ( de abogado) (CS) office

b) (Cin, Rad, TV) studio

c) ( en casa) study; ( apartamento) studio apartment

- estudio fotográfico/de grabación

- estudio jurídico

3) (Mús, Art) study

4) estudios masculino plural (Educ) education

* * *

1)

a) (Educ) ( actividad)

b) (investigación, análisis) study

c) (de asunto, caso) consideration

- estudio de mercado

2) ( lugar)

a) ( de artista) studio; ( de arquitecto) office, studio; ( de abogado) (CS) office

b) (Cin, Rad, TV) studio

c) ( en casa) study; ( apartamento) studio apartment

- estudio fotográfico/de grabación

- estudio jurídico

3) (Mús, Art) study

4) estudios masculino plural (Educ) education

* * *

estudio¹

¹ = studio.

estudio²

² = review, scholarship, study [studies, -pl.], work, calibration, surveying, analysis [analyses, -pl.].

Nota: Proceso de estudio de un todo para encontrar sus partes esenciales y las relaciones existentes entre ellas.

* * *

1 ( Educ)

(actividad): primero está el estudio y después la diversión your studies o work o studying must come first, then you can enjoy yourself

(investigación, análisis): el estudio de la fauna de la zona the study of the area's fauna

realizó un estudio sobre la mortalidad infantil she carried out a survey o study on infant mortality

le hicieron un estudio hormonal she had a series of hormone tests done

3 (de un asunto, caso) consideration

le presentaron un nuevo proyecto para su estudio they put forward a new plan for his consideration

está en o ( RPl) a estudio en el Parlamento it is being considered in parliament

field study

market research

B (lugar)

1 (de un artista) studio; (de un arquitecto) office, studio; (de un abogado) (CS) office

2 ( Cin, Rad, TV) studio

la película se realizará íntegramente en estudios the movie will be made entirely in the studio

3 (en una casa) study

4 (apartamento) studio apartment o ( BrE) flat

recording studio

photographic studio

( RPl) (oficina) lawyer's office; (grupo) legal practise*

1 ( Mús) study, étude

2 ( Art) study

D estudios mpl ( Educ) education

estudios primarios/superiores primary/higher education

está cursando estudios de especialización she is doing her specialization

se sacrificó para darle estudios a su hijo she made a lot of sacrifices to give her son an education o to put her son through school

para ese trabajo no hace falta tener estudios you don't need a degree for that job

¿por qué dejaste los estudios? why did you give up your studies?, why did you quit school? ( AmE)

* * *

1ª persona singular (yo) presente indicativo

3ª persona singular (él/ella/usted) pretérito indicativo

a) ‹ asignatura› to study;

◊ ¿qué carrera estudió? what subject did he do at college/university?

b) ‹ instrumento› to learn

c) ‹lección/tablas› to learn

◊ estudia en un colegio privado he goes to a private school;

a) (Educ) ( actividad):

◊ primero está el estudio studying o your studies o work must come first

b) (investigación, análisis) study;

◊ estudio de mercado market research

c) (de asunto, caso) consideration;

◊ está en estudio it is being considered

a) ( de artista) studio;

b) (Cin, Rad, TV) studio

c) ( en casa) study;

◊ estudios sustantivo masculino plural (Educ) education;

* * *

estudio nm

1. [actividad] study;

ha dedicado muchos años al estudio del tema she has studied the subject for many years;

estar en estudio to be under consideration

2. [investigación] study;

ha publicado un estudio sobre el tema she's published a study on the subject;

hacer un estudio de algo to survey sth;

le hicieron un estudio de la flora intestinal they investigated the composition of her intestinal flora

estudio geológico geological survey;

estudio de impacto ambiental environmental impact study;

estudio de viabilidad feasibility study

3.

el niño va muy bien en los estudios the boy is doing very well at school;

al terminar sus estudios en Viena, viajó a París on completing his studies in Vienna he travelled to Paris;

dar estudios a alguien to pay for o finance sb's education;

dejó los estudios a los quince años he left school at fifteen;

tener estudios to be educated

estudios primarios primary education;

estudios secundarios secondary education;

estudios superiores higher education

4. [despacho] study;

5. [apartamento] studio Br flat o US apartment

6. Cine, Rad & TV studio;

los estudios de la Metro the Metro studios

7. Arte study

8. Mús étude, study;

estudio para piano piano study

* * *

1 disciplina study

2 apartamento studio, Br

studio flat

3 de cine, música studio

estudios (universitarios) pl university education sg ;

tener estudios have a degree;

una persona sin estudios a person with no formal education

* * *

estudio nm

1) : study

2) : studio

3) estudios nmpl

: studies, education

* * *

estudio n

1. (en general) study [pl. studies]

2. (apartamento) studio flat

3. (de televisión, cine) studio

SUBJECT AREA: Photography, film and optics, Recording, Telecommunications

[br]

[br]

[br]

He received no formal education, but was brought up by his father, a distinguished teacher and philosopher. He dabbled in diverse subjects (modern and ancient languages, mathematics, drawing) in 1856–60 when he became an instructor at the institute of the Deaf-Mute at Paris. He became a prolific inventor and poet and took part in artistic life in Paris. In the 1867 Exposition Universelle in Paris, Cros contributed a facsimile telegraph; he deposited with the Académie des Sciences a sealed text on photography which was not opened until 1876. In the meantime he published a small text on a general solution of the problem of colour photography which appeared almost simultaneously with a similar publication by Louis Ducos du Hauron and which gave rise to bitter discussions over priority. He deposited a sealed paper on 18 April 1877 concerning his concept of apparatus for recording and reproduction of sound which he called the paléophone. When it was opened on 3 December 1877 it was not known that T.A. Edison was already active in this field: Cros is considered the conceptual founder of reproducible sound, whereas Edison was the first "to reduce to practice", which is one of the US criteria for patentability.

[br]

SUBJECT AREA: Recording

[br]

[br]

[br]

He was a nobleman and an Italian cavalry lieutenant and went to the USA, where he married Daisy Abbott (of Stamford, Connecticut). From 1888 he made amateur recordings of a wide circle of artistic acquaintances and improved the recording diaphragm attachment by the development of a "spider" (a mechanical link that attacks the diaphragm in several points on its surface, rather than in the centre only). From 1892, through the Bettini Phonograph Laboratories, he published recordings of operatic artists and selections, and this led to the development of improved duplicating techniques by the so-called pantographic method. In 1901 he sold his US company and moved to Paris, although he continued to publish both cylinders and discs. In 1908 Bettini made a venture into cinematography, without success.

[br]

SUBJECT AREA: Broadcasting, Electronics and information technology, Recording, Telecommunications

[br]

[br]

[br]

From an early age he was absorbed by phenomena of physics to the exclusion of all other subjects, including mathematics. When choosing his subjects for the final three years in Borgedydskolen in Christianshavn (Copenhagen) before university, he opted for languages and history. At the University of Copenhagen he embarked on the study of medicine in 1889, but broke it off and was apprenticed to the machine firm of A/S Frichs Eftf. in Aarhus. He was employed between 1893 and 1899 as a mechanic and assistant in the laboratory of the Copenhagen Telephone Company KTAS. Eventually he advanced to be Head of the line fault department. This suited his desire for experiment and measurement perfectly. After the invention of the telegraphone in 1898, he left the laboratory and with responsible business people he created Aktieselskabet Telegrafonen, Patent Poulsen in order to develop it further, together with Peder Oluf Pedersen (1874– 1941). Pedersen brought with him the mathematical background which eventually led to his professorship in electronic engineering in 1922.

The telegraphone was the basis for multinational industrial endeavours after it was demonstrated at the 1900 World's Exhibition in Paris. It must be said that its strength was also its weakness, because the telegraphone was unique in bringing sound recording and reproduction to the telephone field, but the lack of electronic amplifiers delayed its use outside this and the dictation fields (where headphones could be used) until the 1920s. However, commercial interest was great enough to provoke a number of court cases concerning patent infringement, in which Poulsen frequently figured as a witness.

In 1903–4 Poulsen and Pedersen developed the arc generator for continuous radio waves which was used worldwide for radio transmitters in competition with Marconi's spark-generating system. The inspiration for this work came from the research by William Duddell on the musical arc. Whereas Duddell had proposed the use of the oscillations generated in his electric arc for telegraphy in his 1901 UK patent, Poulsen contributed a chamber of hydrogen and a transverse magnetic field which increased the efficiency remarkably. He filed patent applications on these constructions from 1902 and the first publication in a scientific forum took place at the International Electrical Congress in St Louis, Missouri, in 1904.

In order to use continuous waves efficiently (the high frequency constituted a carrier), Poulsen developed both a modulator for telegraphy and a detector for the carrier wave. The modulator was such that even the more primitive spark-communication receivers could be used. Later Poulsen and Pedersen developed frequency-shift keying.

The Amalgamated Radio-Telegraph Company Ltd was launched in London in 1906, combining the developments of Poulsen and those of De Forest Wireless Telegraph Syndicate. Poulsen contributed his English and American patents. When this company was liquidated in 1908, its assets were taken over by Det Kontinentale Syndikat for Poulsen Radio Telegrafi, A/S in Copenhagen (liquidated 1930–1). Some of the patents had been sold to C.Lorenz AG in Berlin, which was very active.

The arc transmitting system was in use worldwide from about 1910 to 1925, and the power increased from 12 kW to 1,000 kW. In 1921 an exceptional transmitter rated at 1,800 kW was erected on Java for communications with the Netherlands. More than one thousand installations had been in use worldwide. The competing systems were initially spark transmitters (Marconi) and later rotary converters ( Westinghouse). Similar power was available from valve transmitters only much later.

From c. 1912 Poulsen did not contribute actively to further development. He led a life as a well-respected engineer and scientist and served on several committees. He had his private laboratory and made experiments in the composition of matter and certain resonance phenomena; however, nothing was published. It has recently been suggested that Poulsen could not have been unaware of Oberlin Smith's work and publication in 1888, but his extreme honesty in technical matters indicates that his development was indeed independent. In the case of the arc generator, Poulsen was always extremely frank about the inspiration he gained from earlier developers' work.

[br]

SUBJECT AREA: Recording

[br]

[br]

[br]

He was the descendant of a Scottish family who emigrated to France in 1688. He trained as a printer and later became a proof corrector in printing houses catering predominantly for scientific publishers. He became interested in shorthand systems and eventually turned his interest to making a permanent record of sounds in air. At the time it was already known (Young, Duhamel, Wertheim) to record vibrations of bodies. He made a theoretical study and deposited under sealed wrapper a note in the Académie des Sciences on 26 January 1857. He approached the scientific instrument maker Froment and was able to pay for the manufacture of one instrument due to support from the Société d'Encouragement à l'Industrie Nationale. This funding body obtained a positive report from the physicist Lissajous on 6 January 1858. A new model phonautograph was constructed in collaboration with the leading scientific instrument maker in Paris at the time, Rudolph Koenig, and a contract was signed in 1859. The instrument was a success, and Koenig published a collection of traces in 1864.

Although the membrane was parallel to the rotating surface, a primitive lever system generated lateral movements of a bristle which scratched curves in a thin layer of lampblack on the rotating surface. The curves were not necessarily representative of the vibrations in the air. Scott did not imagine the need for reproducing a recorded sound; rather, his intention was to obtain a trace that would lend itself to mathematical analysis and visual recognition of sounds. Obviously the latter did not require the same degree of linearity as the former. When Scott learned that similar apparatus had been built independently in the USA, he requested that his sealed wrapper be opened on 15 July 1861 in order to prove his scientific priority. The contract with Koenig left Scott without influence over his instrument, and eventually he became convinced that everyone else, including Edison in the end, had stolen his invention. Towards the end of his life he became interested mainly in the history of printing, and he was involved in the publishing of a series of books about books.

[br]

SUBJECT AREA: Broadcasting, Electronics and information technology, Photography, film and optics, Recording, Telecommunications

[br]

[br]

[br]

De Forest was born into the family of a Congregational minister that moved to Alabama in 1879 when the father became President of a college for African-Americans; this was a position that led to the family's social ostracism by the white community. By the time he was 13 years old, De Forest was already a keen mechanical inventor, and in 1893, rejecting his father's plan for him to become a clergyman, he entered the Sheffield Scientific School of Yale University. Following his first degree, he went on to study the propagation of electromagnetic waves, gaining a PhD in physics in 1899 for his thesis on the "Reflection of Hertzian Waves from the Ends of Parallel Wires", probably the first US thesis in the field of radio.

He then joined the Western Electric Company in Chicago where he helped develop the infant technology of wireless, working his way up from a modest post in the production area to a position in the experimental laboratory. There, working alone after normal working hours, he developed a detector of electromagnetic waves based on an electrolytic device similar to that already invented by Fleming in England. Recognizing his talents, a number of financial backers enabled him to set up his own business in 1902 under the name of De Forest Wireless Telegraphy Company; he was soon demonstrating wireless telegraphy to interested parties and entering into competition with the American Marconi Company.

Despite the failure of this company because of fraud by his partners, he continued his experiments; in 1907, by adding a third electrode, a wire mesh, between the anode and cathode of the thermionic diode invented by Fleming in 1904, he was able to produce the amplifying device now known as the triode valve and achieve a sensitivity of radio-signal reception much greater than possible with the passive carborundum and electrolytic detectors hitherto available. Patented under the name Audion, this new vacuum device was soon successfully used for experimental broadcasts of music and speech in New York and Paris. The invention of the Audion has been described as the beginning of the electronic era. Although much development work was required before its full potential was realized, the Audion opened the way to progress in all areas of sound transmission, recording and reproduction. The patent was challenged by Fleming and it was not until 1943 that De Forest's claim was finally recognized.

Overcoming the near failure of his new company, the De Forest Radio Telephone Company, as well as unsuccessful charges of fraudulent promotion of the Audion, he continued to exploit the potential of his invention. By 1912 he had used transformer-coupling of several Audion stages to achieve high gain at radio frequencies, making long-distance communication a practical proposition, and had applied positive feedback from the Audion output anode to its input grid to realize a stable transmitter oscillator and modulator. These successes led to prolonged patent litigation with Edwin Armstrong and others, and he eventually sold the manufacturing rights, in retrospect often for a pittance.

During the early 1920s De Forest began a fruitful association with T.W.Case, who for around ten years had been working to perfect a moving-picture sound system. De Forest claimed to have had an interest in sound films as early as 1900, and Case now began to supply him with photoelectric cells and primitive sound cameras. He eventually devised a variable-density sound-on-film system utilizing a glow-discharge modulator, the Photion. By 1926 De Forest's Phonofilm had been successfully demonstrated in over fifty theatres and this system became the basis of Movietone. Though his ideas were on the right lines, the technology was insufficiently developed and it was left to others to produce a system acceptable to the film industry. However, De Forest had played a key role in transforming the nature of the film industry; within a space of five years the production of silent films had all but ceased.

In the following decade De Forest applied the Audion to the development of medical diathermy. Finally, after spending most of his working life as an independent inventor and entrepreneur, he worked for a time during the Second World War at the Bell Telephone Laboratories on military applications of electronics.

[br]

KF / JW

SUBJECT AREA: Metallurgy, Ports and shipping

[br]

[br]

[br]

The son of a merchant of Dundee, Kirkaldy was educated there, then at Merchiston Castle School, Edinburgh, and at Edinburgh University. For a while he worked in his father's office, but with a preference for engineering, in 1843 he commenced an apprenticeship at the Glasgow works of Robert Napier. After four years in the shops he was transferred to the drawing office and in a very few years rose to become Chief. Here Kirkaldy demonstrated a remarkable talent both for the meticulous recording of observations and data and for technical drawing. His work also had an aesthetic appeal and four of his drawings of Napier steamships were shown at the Paris Exhibition of 1855, earning both Napier and Kirkaldy a medal. His "as fitted" set of drawings of the Cunard Liner Persia, which had been built in 1855, is now in the possession of the National Maritime Museum at Greenwich, London; it is regarded as one of the finest examples of its kind in the world, and has even been exhibited at the Royal Academy in London.

With the impending order for the Royal Naval Ironclad Black Prince (sister ship to HMS Warrior, now preserved at Portsmouth) and for some high-pressure marine boilers and engines, there was need for a close scientific analysis of the physical properties of iron and steel. Kirkaldy, now designated Chief Draughtsman and Calculator, was placed in charge of this work, which included comparisons of puddled steel and wrought iron, using a simple lever-arm testing machine. The tests lasted some three years and resulted in Kirkaldy's most important publication, Experiments on Wrought Iron and Steel (1862, London), which gained him wide recognition for his careful and thorough work. Napier's did not encourage him to continue testing; but realizing the growing importance of materials testing, Kirkaldy resigned from the shipyard in 1861. For the next two and a half years Kirkaldy worked on the design of a massive testing machine that was manufactured in Leeds and installed in premises in London, at The Grove, Southwark.

The works was open for trade in January 1866 and engineers soon began to bring him specimens for testing on the great machine: Joseph Cubitt (son of William Cubitt) brought him samples of the materials for the new Blackfriars Bridge, which was then under construction. Soon The Grove became too cramped and Kirkaldy moved to 99 Southwark Street, reopening in January 1874. In the years that followed, Kirkaldy gained a worldwide reputation for rigorous and meticulous testing and recording of results, coupled with the highest integrity. He numbered the most distinguished engineers of the time among his clients.

After Kirkaldy's death, his son William George, whom he had taken into partnership, carried on the business. When the son died in 1914, his widow took charge until her death in 1938, when the grandson David became proprietor. He sold out to Treharne \& Davies, chemical consultants, in 1965, but the works finally closed in 1974. The future of the premises and the testing machine at first seemed threatened, but that has now been secured and the machine is once more in working order. Over almost one hundred years of trading in South London, the company was involved in many famous enquiries, including the analysis of the iron from the ill-fated Tay Bridge (see Bouch, Sir Thomas).

[br]

LRD / FMW

SUBJECT AREA: Photography, film and optics

[br]

[br]

[br]

Born of English parents and educated in Paris, Acres travelled to England in the 1880s. He worked for the photographic manufacturing firm Elliott \& Co. in Barnet, near London, and became the Manager. He became well known through his frequent lectures, demonstrations and articles in the photographic press. The appearance of the Edison kinetoscope in 1893 seems to have aroused his interest in the recording and reproduction of movement.

At the beginning of 1895 he took his idea for a camera to Robert Paul, an instrument maker, and they collaborated on the building of a working camera, which Acres used to record the Oxford and Cambridge Boat Race on 30 March 1895. He filmed the Derby at Epsom on 29 May and the opening of the Kiel Canal in June, as well as ten other subjects for the kinetoscope, which were sold by Paul. Acres's association with Paul ended in July 1895. Acres had patented the camera design, the Kinetic Lantern, on 27 May 1895 and then went on to design a projector with which he gave the first successful presentation of projected motion pictures to take place in Britain, at the Royal Photographic Society's meeting on 14 January 1896. At the end of the month Acres formed his own business, the Northern Photographic Company, to supply film stock, process and print exposed film, and to make finished film productions.

His first shows to the public, using the renamed Kineopticon projector, started in Piccadilly Circus on 21 March 1896. He later toured the country with his show. He was honoured with a Royal Command Performance at Marlborough House on 21 July 1896 before members of the royal family. Although he made a number of films for his own use, they and his equipment were used only for his own demonstrations. His last contribution to cinematography was the design and patenting in 1898 of the first low-cost system for amateur use, the Birtac, which was first shown on 25 January 1899 and marketed in May of that year. It used half-width film, 17.5 mm wide, and the apparatus served as camera, printer and projector.

[br]

SUBJECT AREA: Architecture and building, Automotive engineering, Electricity, Electronics and information technology, Metallurgy, Photography, film and optics, Public utilities, Recording, Telecommunications

[br]

[br]

[br]

He was the son of Samuel Edison, who was in the timber business. His schooling was delayed due to scarlet fever until 1855, when he was 8½ years old, but he was an avid reader. By the age of 14 he had a job as a newsboy on the railway from Port Huron to Detroit, a distance of sixty-three miles (101 km). He worked a fourteen-hour day with a stopover of five hours, which he spent in the Detroit Free Library. He also sold sweets on the train and, later, fruit and vegetables, and was soon making a profit of $20 a week. He then started two stores in Port Huron and used a spare freight car as a laboratory. He added a hand-printing press to produce 400 copies weekly of The Grand Trunk Herald, most of which he compiled and edited himself. He set himself to learn telegraphy from the station agent at Mount Clements, whose son he had saved from being run over by a freight car.

At the age of 16 he became a telegraphist at Port Huron. In 1863 he became railway telegraphist at the busy Stratford Junction of the Grand Trunk Railroad, arranging a clock with a notched wheel to give the hourly signal which was to prove that he was awake and at his post! He left hurriedly after failing to hold a train which was nearly involved in a head-on collision. He usually worked the night shift, allowing himself time for experiments during the day. His first invention was an arrangement of two Morse registers so that a high-speed input could be decoded at a slower speed. Moving from place to place he held many positions as a telegraphist. In Boston he invented an automatic vote recorder for Congress and patented it, but the idea was rejected. This was the first of a total of 1180 patents that he was to take out during his lifetime. After six years he resigned from the Western Union Company to devote all his time to invention, his next idea being an improved ticker-tape machine for stockbrokers. He developed a duplex telegraphy system, but this was turned down by the Western Union Company. He then moved to New York.

Edison found accommodation in the battery room of Law's Gold Reporting Company, sleeping in the cellar, and there his repair of a broken transmitter marked him as someone of special talents. His superior soon resigned, and he was promoted with a salary of $300 a month. Western Union paid him $40,000 for the sole rights on future improvements on the duplex telegraph, and he moved to Ward Street, Newark, New Jersey, where he employed a gathering of specialist engineers. Within a year, he married one of his employees, Mary Stilwell, when she was only 16: a daughter, Marion, was born in 1872, and two sons, Thomas and William, in 1876 and 1879, respectively.

He continued to work on the automatic telegraph, a device to send out messages faster than they could be tapped out by hand: that is, over fifty words per minute or so. An earlier machine by Alexander Bain worked at up to 400 words per minute, but was not good over long distances. Edison agreed to work on improving this feature of Bain's machine for the Automatic Telegraph Company (ATC) for $40,000. He improved it to a working speed of 500 words per minute and ran a test between Washington and New York. Hoping to sell their equipment to the Post Office in Britain, ATC sent Edison to England in 1873 to negotiate. A 500-word message was to be sent from Liverpool to London every half-hour for six hours, followed by tests on 2,200 miles (3,540 km) of cable at Greenwich. Only confused results were obtained due to induction in the cable, which lay coiled in a water tank. Edison returned to New York, where he worked on his quadruplex telegraph system, tests of which proved a success between New York and Albany in December 1874. Unfortunately, simultaneous negotiation with Western Union and ATC resulted in a lawsuit.

Alexander Graham Bell was granted a patent for a telephone in March 1876 while Edison was still working on the same idea. His improvements allowed the device to operate over a distance of hundreds of miles instead of only a few miles. Tests were carried out over the 106 miles (170 km) between New York and Philadelphia. Edison applied for a patent on the carbon-button transmitter in April 1877, Western Union agreeing to pay him $6,000 a year for the seventeen-year duration of the patent. In these years he was also working on the development of the electric lamp and on a duplicating machine which would make up to 3,000 copies from a stencil. In 1876–7 he moved from Newark to Menlo Park, twenty-four miles (39 km) from New York on the Pennsylvania Railway, near Elizabeth. He had bought a house there around which he built the premises that would become his "inventions factory". It was there that he began the use of his 200- page pocket notebooks, each of which lasted him about two weeks, so prolific were his ideas. When he died he left 3,400 of them filled with notes and sketches.

Late in 1877 he applied for a patent for a phonograph which was granted on 19 February 1878, and by the end of the year he had formed a company to manufacture this totally new product. At the time, Edison saw the device primarily as a business aid rather than for entertainment, rather as a dictating machine. In August 1878 he was granted a British patent. In July 1878 he tried to measure the heat from the solar corona at a solar eclipse viewed from Rawlins, Wyoming, but his "tasimeter" was too sensitive.

Probably his greatest achievement was "The Subdivision of the Electric Light" or the "glow bulb". He tried many materials for the filament before settling on carbon. He gave a demonstration of electric light by lighting up Menlo Park and inviting the public. Edison was, of course, faced with the problem of inventing and producing all the ancillaries which go to make up the electrical system of generation and distribution-meters, fuses, insulation, switches, cabling—even generators had to be designed and built; everything was new. He started a number of manufacturing companies to produce the various components needed.

In 1881 he built the world's largest generator, which weighed 27 tons, to light 1,200 lamps at the Paris Exhibition. It was later moved to England to be used in the world's first central power station with steam engine drive at Holborn Viaduct, London. In September 1882 he started up his Pearl Street Generating Station in New York, which led to a worldwide increase in the application of electric power, particularly for lighting. At the same time as these developments, he built a 1,300yd (1,190m) electric railway at Menlo Park.

On 9 August 1884 his wife died of typhoid. Using his telegraphic skills, he proposed to 19-year-old Mina Miller in Morse code while in the company of others on a train. He married her in February 1885 before buying a new house and estate at West Orange, New Jersey, building a new laboratory not far away in the Orange Valley.

Edison used direct current which was limited to around 250 volts. Alternating current was largely developed by George Westinghouse and Nicola Tesla, using transformers to step up the current to a higher voltage for long-distance transmission. The use of AC gradually overtook the Edison DC system.

In autumn 1888 he patented a form of cinephotography, the kinetoscope, obtaining film-stock from George Eastman. In 1893 he set up the first film studio, which was pivoted so as to catch the sun, with a hinged roof which could be raised. In 1894 kinetoscope parlours with "peep shows" were starting up in cities all over America. Competition came from the Latham Brothers with a screen-projection machine, which Edison answered with his "Vitascope", shown in New York in 1896. This showed pictures with accompanying sound, but there was some difficulty with synchronization. Edison also experimented with captions at this early date.

In 1880 he filed a patent for a magnetic ore separator, the first of nearly sixty. He bought up deposits of low-grade iron ore which had been developed in the north of New Jersey. The process was a commercial success until the discovery of iron-rich ore in Minnesota rendered it uneconomic and uncompetitive. In 1898 cement rock was discovered in New Village, west of West Orange. Edison bought the land and started cement manufacture, using kilns twice the normal length and using half as much fuel to heat them as the normal type of kiln. In 1893 he met Henry Ford, who was building his second car, at an Edison convention. This started him on the development of a battery for an electric car on which he made over 9,000 experiments. In 1903 he sold his patent for wireless telegraphy "for a song" to Guglielmo Marconi.

In 1910 Edison designed a prefabricated concrete house. In December 1914 fire destroyed three-quarters of the West Orange plant, but it was at once rebuilt, and with the threat of war Edison started to set up his own plants for making all the chemicals that he had previously been buying from Europe, such as carbolic acid, phenol, benzol, aniline dyes, etc. He was appointed President of the Navy Consulting Board, for whom, he said, he made some forty-five inventions, "but they were pigeonholed, every one of them". Thus did Edison find that the Navy did not take kindly to civilian interference.

In 1927 he started the Edison Botanic Research Company, founded with similar investment from Ford and Firestone with the object of finding a substitute for overseas-produced rubber. In the first year he tested no fewer than 3,327 possible plants, in the second year, over 1,400, eventually developing a variety of Golden Rod which grew to 14 ft (4.3 m) in height. However, all this effort and money was wasted, due to the discovery of synthetic rubber.

In October 1929 he was present at Henry Ford's opening of his Dearborn Museum to celebrate the fiftieth anniversary of the incandescent lamp, including a replica of the Menlo Park laboratory. He was awarded the Congressional Gold Medal and was elected to the American Academy of Sciences. He died in 1931 at his home, Glenmont; throughout the USA, lights were dimmed temporarily on the day of his funeral.

[br]