Joubert, Jules François

SUBJECT AREA: Electricity

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b. 1834 Tours, France

d. 1910 Paris, France

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French physicist, investigator of alternating-current wave-forms.

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Joubert became Professor of Physics in the Collège Rollin, Paris, in 1874, a position he held until 1888. He was at one time General Secretary of the Société Française de Physique. In collaboration with Pasteur he began studies into the theories of germs and bacteria. In 1880 Joubert carried out research on wave-forms in alternating-current arc-lighting circuits. Reinventing a method previously used by earlier experimenters, including Wheatstone, he was, by a mechanical sampling technique, able to determine the voltage at different points in the cycle. By using a rotating contact on the alternator shaft, the angular position of which could be varied, the whole of the wave-form could be delineated. This successful technique was widely used for some thirty years.

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Bibliography

1880, "Sur les courants alternatifs et la force électromotive de l'arc électrique", Journal of Physics 9:297–303 (describes his experiments).

Further Reading

"Investigation of alternating current arcs", Electrician (1880) 5:151–2 (a report on Joubert's method).

V.J.Phillips, 1987, Waveforms, Bristol (an extensive account of early methods of wave-form observation).

W.Bulloch, 1938, The History of Bacteriology, Oxford; 1979, repub. New York.

See also: Duddell, William du Bois

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