SIR

See also:

• WILLIAM
• WILLIAM (1143-1214)
• WILLIAM (1227-1256)
• WILLIAM (1J33-1584)
• WILLIAM (A.S. Wilhelm, O. Norse Vilhidlmr; O. H. Ger. Willahelm, Willahalm, M. H. Ger. Willehelm, Willehalm, Mod.Ger. Wilhelm; Du. Willem; O. Fr. Villalme, Mod. Fr. Guillaume; from " will," Goth. vilja, and " helm," Goth. hilms, Old Norse hidlmr, meaning
• WILLIAM (c. 1130-C. 1190)
• WILLIAM, 13TH

WILLIAM

See also:

• SIR WILLIAM HUGGINS (1824-1910)

HUGGINS (1824-1910)  , English astronomer, was born in London on the 7th of February 1824, and was educated first at the City of London School and then under various private teachers . Having determined to apply himself to the study of astronomy, he built in 1856 a private observatory at Tulse Hill, in the south of London . At first he occupied himself with ordinary routine work, but being far from satisfied with the scope which this afforded, he seized eagerly upon the opportunity for novel research, offered by Kirchhoff's discoveries in spectrum analysis . The chemical constitution of the stars was the problem to which he turned his attention, and his first results, obtained in conjunction with Professor W . A . Miller, were presented to the Royal Society in 1863, in a preliminary note on the " Lines of some of the fixed stars." His experiments, in the same year, on the photographic registration of stellar spectra, marked an innovation of a momentous character . But the wet collodion process was then the only one available, and its inconveniences were such as to preclude its extensive employment; the real triumphs of photographic astronomy began in 1875 with Huggins's adoption and adaptation of the gelatine dry plate . This enabled the observer to make exposures of any desired length, and, through the cumulative action of light on extremely sensitive surfaces, to obtain permanent accurate pictures of celestial objects so faint as to be completely invisible to the eye, even when aided by the most powerful telescopes . In the last quarter of the 19th century spectroscopy and photography together worked a revolution in observational astronomy, and in both branches Huggins acted as pioneer . Many results of great importance are associated with his name . Thus in 1 864 the spectroscope yielded him evidence that planetary and irregular nebulae consist of luminous gas—a conclusion tending to support the nebular hypothesis of the origin of stars and planets by condensation from glowing masses of fluid material . On the 18th of May 1866 he made the first spectroscopic examination of a temporary star (Nova Coronae), and found it to be enveloped in blazing hydrogen .

In 1868 he proved incandescent

carbon-vapours to be the main source of cometary light; and on the 23rd of April in the same year applied Doppler's principle to the detection and measurement of stellar velocities in the line of sight . Data of this kind, which are by other means inaccessible to the astronomer, are obviously indispensable to- any adequate conception of the stellar system as a whole or in its parts . In solar physics Huggins suggested a spectroscopic method for viewing the red prominences in daylight; and his experiments went far towards settling a much-disputed question regarding the solar distribution of calcium . In the general solar spectrum this element is represented by a large number of lines, but in the spectrum of the prominences and chromosphere one pair only can be detected . This circumstance appeared so anomalous that some astronomers doubted whether the surviving lines were really due to calcium; but Sir William and Lady Huggins (nee Margaret Lindsay Murray, who, after their marriage in 1875, actively assisted her husband) successfully demonstrated in the laboratory that :alcium vapour, if at a sufficiently low pressure, gives under the influence of the electric discharge precisely these lines and no others . The striking discovery was, in 1903, made by the same investigators that the spontaneous luminosity of radium gives a spectrum of a kind never before obtained without the aid of powerful excitation, electrical or thermal . It consists, that is to say, in a range of bright lines, the agreement of which with the negative pole bands of nitrogen, together with details of interest connected with its mode of production, was ascertained by a continuance of the research . Sir William Huggins, who was made K.C.B. in 1897, received the Order of Merit in 1902, and was awarded many honours, academic and other . He presided over the meeting of the British Association in 1891, and during the five years 1900–1905 acted as president of the Royal Society, from which he at different times received a Royal, a Copley and a Rumford medal . Four of his presidential addresses were republished in 1906, in an illustrated volume entitled The Royal Society . A list of his scientific papers is contained in chapter ii. of the magnificent Atlas of Representative Stellar Spectra, published in 1899, by Sir William and Lady Huggins conjointly, for which they were adjudged the Actonian prize of the Royal Institution . Sir William Huggins died on the 12th of May 1910 .

See ch. i. of Atlas of Stellar Spectra, containing a

history of the Tulse Hill observatory; Sir W . Huggins's personal retrospect in the Nineteenth Century for June 1897; " Scientific Worthies," with photogravure portrait (Nature); Astronomers of To-Day, by Hector Macpherson, junr . (1905) (portrait); Month . Notices Roy . Astr . Society, xxvii . 146 (C . Pritchard) . (A . M .