(interested+in+birds)

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- ornithological

- ornithological

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ornitoloģija

- ornithological

n. ornitologi, läran om fåglarna

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- ornithological

- ornithological

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- ornithological

- ornithological

- ornithological

- ornithological

- ornithological

SUBJECT AREA: Medical technology, Photography, film and optics

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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.

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See also: Demenÿ, Georges

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SUBJECT AREA: Electronics and information technology

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Pierce entered the University of Texas in 1890, gaining his BSc in physics in 1893 and his MSc in 1894. After teaching and doing various odd jobs, in 1897 he obtained a scholarship to Harvard, obtaining his PhD three years later. Following a period at the University of Leipzig, he returned to the USA in 1903 to join the teaching staff at Harvard, where he soon established new courses and began to gain a reputation as a pioneer in electronics, including the study of crystal rectifiers and publication of a textbook on wireless telegraphy. In 1912, with Kennelly, he conceived the idea of motional impedance. The same year he was made first Director of Harvard's Cruft High- Tension Electrical Laboratory, a post he held until his retirement. In 1917 he was appointed Professor of Physics, and for the remainder of the First World War he was also involved in work on submarine detection at the US Naval Base in New London. In 1921 he was appointed Rumford Professor of Physics and became interested in the work of Walter Cady on crystal-controlled circuits. As a result of this he patented the Pierce crystal oscillator in 1924. Having discovered the magnetostriction property of nickel and nichrome, in 1928 he also invented the magnetostriction oscillator. The mercury-vapour discharge lamp is also said to have been his idea. He became Gordon McKay Professor of Physics and Communications in 1935 and retired from Harvard in 1940, but he remained active for the rest of his life with the study of sound generation by birds and insects.

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SUBJECT AREA: Aerospace

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Wenham trained as a marine engineer and later specialized in screw propellers and high-pressure engines. He had many interests. He took his steamboat to the Nile and assisted the photographer F.Frith to photograph Egyptian tombs by devising a series of mirrors to deflect sunlight into the dark recesses. He experimented with gas engines and produced a hot-air engine. Wenham was a leading, if controversial, figure in the Microscopical Society and a member of the Royal Photographic Society; he developed an enlarger.

Wenham was interested in both mechanical and lighter-than-air flight. One of his friends was James Glaisher, a well-known balloonist who made many ascents to gather scientific information. When the (Royal) Aeronautical Society of Great Britain was founded in 1866, the Rules were drawn up by Wenham, Glaisher and the Honorary Secretary, F.W.Brearey. At the first meeting of the Society, on 27 June 1866, "On aerial locomotion and the laws by which heavy bodies impelled through the air are sustained" was read by Wenham. In his paper Wenham described his experiments with a whirling arm (used earlier by Cayley) to measure lift and drag on flat surfaces inclined at various angles of incidence. His studies of birds' wings and, in particular, their wing loading, showed that they derived most of their lift from the front portion, hence a long, thin wing was better than a short, wide one. He published illustrations of his glider designs covering his experiments of c. 1858–9. One of these had five slender wings one above the other, an idea later developed by Horatio Phillips. Wenham had some success with a model, but no real success with his full-size gliders.

In 1871, Wenham and John Browning constructed the first wind tunnel designed for aeronautical research. It utilized a fan driven by a steam engine to propel the air and had a working section of 18 in. (116 cm). Wenham continued to play an important role in aeronautical matters for many years, including a lengthy exchange of ideas with Octave Chanute from 1892 onwards.

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