Mechain, Peter Francis Andrew

, a very able French mathematician and astronomer, was born at Laon in 17 44, where his father was an architect, and at one time a man of considerable property. At an early age he discovered a strong inclination for mathematical pursuits, and while he was under the instruction of his tutors, corresponded with Lalande, whom he was desirous of assisting in his labours. In 1772, Mechain was invited to Paris, where he was employed at the depot of the marine, and assisted M. Darquier in correcting his observations. Here his merit brought him acquainted with M. Doisy, director of the depot, who gave him a more advantageous situation at Versailles. At this place he diligently observed the | heavens, and, in 1774, sent to the Royal Academy of Sciences “A Memoir relative to an Eclipse of Aldebaran,” observed by him on the 15th of April. He calculated the orbit of the comet of 1774, and discovered that of 1781. In 1782, he gained the prize of the academy on the subject of the comet of 1661, the return of which was eagerly expected in 1790; and in the same year he was admitted a member of the academy, and soon selected for the superintendance of the Connoissance des Tems. In 1790, M. Mechain discoveredhis eighth comet, and communicated to the academy his observations on it, together with his calculations of its orbit. In 1792 he undertook, conjointly with M. Delambre, the labour of measuring the degrees of the meridian, for the purpose of more accurately determining the magnitude of the earth and the length of a metre. In the month of June 1792, M. Mechain set out to measure the triangles between Perpignan and Barcelona; and notwithstanding that the war occasioned a temporary suspension of his labours, he was enabled to resume and complete them during the following year. He died on the 20th of September 1805, at Castellon de la Plana, in the sixty-second year of his age. Lalande deplores his loss as that of not only one of the best French astronomers, but one of the most laborious, the most courageous, and the most robust. His last observations and calculations of the eclipse of the sun on the llth of February, are inserted in the Connoissance des Tems for the year 15; and he also published a great many in the Ephemerides of M. Bode, of Berlin, which he preferred to a former work after Lalande became its editor. A more extensive memoir of his labours may be seen in Baron von Zach’s Journal for July 1800, and Lalande’s History of Astronomy for 1804. 1


Rees’s Cyclopædia.