AIRY, ar'i. Ste GEORr.E BIDDELL (1301-921. An English astronomer. He was horn at Alnwirk. Northumberland. and graduated at Trinity Col lege, Cambridge, in 1819. In 1S25, lie discovered the optical defect of astigmatism and provided a corrective for it. lie was elected to the Plu mian professorship at Cambridge in 1S25, and intrusted with the management of the Cambridge Observatory, the results of his labors being pub lished in the compilation entitled Astronomical Observations, 9 volumes (Cambridge, IS29-38), which became the model of all analogous works since published in Great Britain. In 1S30 he sue ceeded Pond as royal astronomer of the Clreen wich Observato•y.where he introduced or perfect ed numerous astronomical instruments, devised clearer and quicker methods of calculation, and inst it nted valuable researches in magnet ism, meteorology, and photography. One of his most important achievements was the establishment of a mechanical device in the form of magnets and iron, whereby the disturbance of the compass iron-built vessels can be rectified. It was he,
also, who conducted the astronomical obser•a tions preparatory to the definition of the bound ary between Canada and the United States. Among the works written by this distinmlished scientist during his exceptionally long and useful career, the following are especially noteworthy: Graritation, for the Cyclopedia, also pub lished separately (1885) ; Mathematical Tracts on Physical Astronomy (fourth edition, 185SI ; Ipswich Lectures on .1stronomy (fourth edition, 1858) ; Treatises on Errors of Observation ( 1861 ) ; Sound (1Sti9) ; a gnet ism ( 1 S17 ) ; "Trigonometry," "Figure of the "Tide and Waves," in Encyclopedia Metropolitana.
il'i•sh-hiT51'. See AL.t-KtL.