René Baillaud (10 November 1885 – 2 July 1977) was a French

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, natural satellite, moons, comets and galaxy, g ...

born in

Toulouse Toulouse ( , ; oc, Tolosa ) is the prefecture of the French department of Haute-Garonne and of the larger region of Occitania. The city is on the banks of the River Garonne, from the Mediterranean Sea, from the Atlantic Ocean and from Par ...

. He is noted for inventing the paraboloid for detecting incoming aircraft sounds before the introduction of

radar Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...

. It is a parabolic device that reflected the sound of the aircraft towards the ear of the observers.

Biography

Baillaud initially worked at the observatories of

Nice Nice ( , ; Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative c ...

from 1910 to 1924 and of

Marseille Marseille ( , , ; also spelled in English as Marseilles; oc, Marselha ) is the prefecture of the French department of Bouches-du-Rhône and capital of the Provence-Alpes-Côte d'Azur region. Situated in the camargue region of southern Franc ...

from 1924 to 1930. He was also teaching at the "École d'Ingénieurs de Marseille", before taking a chair as professor at the

University of Besançon A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, t ...

and becoming director of the Besançon observatory until 1957. During this time he oversees the installation of special clock, in a specially built room 5 meter underneath the observatories' library to maintain constant temperature, allowing the observatory to join the establishment of a global time network. Baillaud was one of the scientists recruited by General Gustave-Auguste Ferrié to build France's acoustic defense during the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. The group included the celebrated physicist Jean Perrin, a future Nobel laureate.

Works

Paraboloid

This instrument made it possible to establish the position of planes without having to see them, using only the sound they produced. The first prototype was made of wood and measured 60 cm in diameter. The precision of the instrument was such, that it was used during the First World War by the French military to repel night attacks from German bombers by pointing searchlights at them. This furthermore represented a rare technological superiority for the French. After this remarkable start in the fields of acoustics, he nonetheless decided to abandon this field. The reason being that his professor's own instrument didn't get chosen by the French military, and René feared he would have no academic future in this field. He then turned chronometry. He is a founding member of the French society of chronometry, and its first chief of staff, creating in 1931 the journal "Annales Françaises de Chronométrie". In order to join the global mapping project "Carte du Ciel" (directed by his brother), he oversees the installation of a specific instrument: "astrographe triple" dedicated to this purpose. He published his autobiography ''Souvenirs d'un jeune Toulousain'' (1885) and ''Souvenirs: parents et amis de Toulouse et de l'Aveyron, d'un siecle a l'autre'' (1976). The first publication served as an account of the development of the French acoustic defense. René Baillaud is one of the eight children of

Benjamin Baillaud Édouard Benjamin Baillaud (14 February 1848 – 8 July 1934) was a French astronomer. Biography Born in Chalon-sur-Saône, Baillaud studied at the École Normale Supérieure (1866-1869) and the University of Paris. He worked as an assi ...

, and the brother of Jules Baillaud and Émile Baillaud.

Bibliography

*René Baillaud, Baillaud, famille d'astronomes, Besançon, rédaction à la demande de la Sächsische Akademie der Wissenschaften zu Leipzig (J.C. Poggendorff bibliographisch-litterarisches Handwörterbuch, Band VII b), 1967 *Unité de temps, William Markowitz, Paul Libessart, René Baillaud Observatoire national de Besançon, 1955 *Annales Françaises De Chronométrie. 1948–1949 Baillaud (René); Haag (Jules) *Détermination de l'heure au moyen de l'instrument photographique des hauteurs égales, par René Baillaud. Presses universitaires de France, 1923

External links

Soundmirrors.org: Photo of Baillaud paraboloid

TVieuxalbums.baillaud.eu: Personal photo album of René Baillaud

References

{{DEFAULTSORT:Baillaud, Rene 1885 births 1977 deaths 20th-century French astronomers Radar pioneers 20th-century French engineers 20th-century French inventors Scientists from Toulouse