ARGELANDER, Friedrich Wilhelm August, a distinguished German astronomer, was born at Memel, 22d March 1799; and died at Bonn, 17th February 1875. He studied at the university of Königsberg, where his attention was attracted to the study of astronomy by Bessel, whose assistant he became in 1821. In the following year he published an essay on the path of the great comet of 1811, the period of which he determined with great accuracy. In 1823 he was made superintendent of the observatory at Abo; and in 1832 was transferred to the university of Helsingfors, where he remained for five years. In 1837 he published an admirable essay upon the proper motion of the solar system, and in the same year was appointed professor of astronomy at Bonn, where he spent the remainder of his Efe. Argelander ’ s fame rests principaEy on the extensive and accurate observations he undertook in continuation of the plan laid down by Bessel. His results were pubhshed in the Observationes Astronomicoe Abooe factoe, 3 vols., 1830-32; DLX Stellarum Fixarum, Positiones Medioe, 1835; Durchmusterung des nord. Himmels zwischen 45° und 80° nor dl. Breite, 1846; and in the Stemver zeichniss, containing upwards of 210,000 stars, in the ‘3d and 4th vols, of the Astron. Beobacht, auf der Sternwarte zu Bonn. The Neue Uranographie, 1843, and the Atlas des nordl. gestirnten Himmels, 1857, are also valuable works. For several years before his death, Argelander was engaged in observations on stars of variable magnitude and brilliancy, and the results of his labours wiU probably be put forth in a collected form.