Academy of Science was appointed in March 1828 assistant astronomer at the observatory of Bogenthausen, near Munich, and through Schelling's influence, on 18 July 1835, director of the same establishment, with a yearly salary of eleven hundred florins. With a ten and a half inch equatoreal telescope by Mers. mounted in 1835, Lamont observed Halley's comet from 37 Jan. to 17 Mar 1836, Encke's comet in 1838, and the satellites of Batum and Uranus respectively in 1836 and 1837, deducing the orbits of Enceladus and Tethys, besides an improved value for the mass of Uranus (Memoirs Royal Astronomical Society, xi. 5l). In 1836-7 he measured some of the principal nebulæ and clusters (Annalen der kön. Sternwarte, xvii. 306), His zone-observations of 34,674 small stars between latitude +27° and —33°, in the course of which he twice, in 1845-6, uaconsciously observed the planet Neptune, were his most important astronomical work. The resulting eleven catalogues are contained in six volumes (1866-74) supplementary to the 'Annalen' of the observatory. Some additional observations by Lamont were published by Seeliger in 1884 (Suppl. Band xiv.) Lamont observed the total solar eclipses of 8 July 1842 and 18 July 1860, the latter at Castellon de la Plana in Spain, and discussed the attendant phenomena (Phil. Mag. xix 416, 1860; Fortschritte der Physik, xvi. 569). He led the way in adopting the chronographic mode of registering transits; described in 1839 the 'ghost-micrometer' (Jahrbuch der Sternwarte, iii. 187) ; and received the order of the Iron Crown from the emperor of Austria for connecting the Austrian and Bavarian surveys.
His services to terrestrial magnetism began in 1836 with the establishment of a system of daily observations adopted internationally in 1840, when a magnetic observatory was built, under his directions, at Bogenhausen. A set of instruments designed by him for determining the magnetic elements came into extensive use, and with his 'travelling theodolite' be executed magnetic surveys of Bavaria (1849-62), France and Spain (1856-7), North Germany and Denmark (1858). The results were published at Munich, 1854-6, in 'Magnetische Ortebestimmungen ausgiführt an verschiedenen Punkten des Königreichs Baiern' (with an Alias in folio) ; followed in 1858 by 'Untersuchungen über die Bichtung und Stärke des Erdmagnetismus an verschiedenen Punkten des südwestlichen Europa.' end in 1859 by 'Untersuchungen in Nord-Deutschland.' The discovery of the decennial magnetic period was announced by Lamont in September 1850 (Annalen der Physik, lxxxiv, 580); that of the 'earth-current' in 'Der Erdstrom und der Zusammenhang desselben mit dem Magetismus der Erde' (Leipsig, 1862), a work of great prac ical importance in telegraphy ; while his studies in atmospheric electricity led him to the conclusion of a constant negative charge in the earth (ib. lxxxv. 494). From 1838 Bogenhausen became, through his exertions, a meteorological centre; he founded a meteorological association which spread over Germany, but was obliged, for lack of funds, to suspend after three years the publication of the valuable Annalen für Meteorologie und Erd-Magnetismus' (1842-4).
Lamont was associated with the Royal Astronomical Society in 1837, with the Royal Societies of Edinburgh and London respectively in 1845 and 1862, and was appointed in 1852 professor of astronomy in the university of Munich. He was a member of most of the scientific academies of Europe, and among the orders with which he was decorated were those of Gregory the Great (conferred by Pius IS),of the Northern Star of Sweden, and of the Crown of Bavaria, the last carrying with it a title of nobility. He led a tranquil, solitary life, never married, and was indifferent to ordinary enjoyments. He often, however, took part tn the reunions of the 'catholic casino' at Munich. He was personally frugal, liberal to charities, and endowed the university of Munich with a sum of forty-two thousand florins for the support of mathematical students. He established a workshop at the observatory, and was his own mechanician. Small in stature, with sharply cut features, and large, mild blue eyes, he posseseed a constitution without flaw, except through an injury to the spinal marrow, received in a fall from horse when a boy. He died from its effects on 6 Aug. 1875, and was buried in the churchyard at Bogenhausen.
Among his principal works are : l.'Handbuch des Erdmagneliamus,' Berlin, 1849. 2, 'Astronomic und Erdmagnetismus.' Stuttgart, 1851. 3. Handhuch des Magnetismus' (Allgemeine Encyclopëdie der Physik, Band xv.), Leipzig, 1807. The titles of 107 memoirs by him — many of them highly authoritative—are enumerated in the Royal Society's Catalogue of Scientific Papers, and he published from theobservatory ten volumes of 'Observationes Astronomicæ,' thirty-four of 'Annalen der Sternwarte,' and four volumes of 'Jahrbücher' (1838-41).
[Allgemaine Deutsche Biogiapbie (Günther); Historische-Politische Blätter, Band lxxxv. (Schafhäutl); Viertejahrsschrift des Astronomischen Gesellschaft. xv. 60 (C. von Orff); Monthly Notices Royal Astronomical Soc. xl. 203; Nature,