458 ASTRONOMICAL OBSERVATORIES. 



Paris, France. 



I. Ohscrvatoirc Nationale. 



Longitude from Greenwich, 9"' 21.02* E. 

 Latitude, 48° 50' 11.8" N. 

 Dircctorfi : J. T). Cassini, 1071. 

 J. Cassini, 1712. 



C. F. Cassini (de Tliury), 175G. 

 J. D. Cassini (de Thury), 1784. 

 J. J. L. De La Lande, 1795. 

 P. Mechain, 1801. 



A. Brunard, 1804, 



D. F. J. Arago, 1811. 



U. J. J. Le Verrier, 1853. 



C. E. Delaunay, 1871. 



U. J. J. Le Verrier, 1872, 



E. Mouchez, 1878. 



National Observatory (formerly royal, since imperial), built in 1667, 

 under the auspices of the Academy of Sciences, according to plans of 

 C, Perrault. a vast ceutral hall ; two towers, east aud west. In 1732 

 a small room to accommodate a mural quadrant was added beyond the 

 eastern tower, and in 1742 this was extended by a second inclosure 

 for a movable quadrant. In 1700 a turret, with a revolving roof, was 

 built to the south of this addition. The main building, having become 

 dilapidated, was restored in 1780, completed 1793; since when it has 

 been detached aud the south terrace built. In 1832 the small rooms 

 where observations are taken were re])aired, and the amphitheater and 

 a rotunda with a revolving roof built upon the principal terrace. The 

 dome intended for the shelter of the great equatorial was placed on the 

 summit of the building in 1850. The great telescope, with a mirror of 

 silvered glass, 4 feet (1.2™) in diameter, Avas mounted in 1870, in a build- 

 ing on the ground -floor level. John Dominic Cassini discovered four 

 of the satellites of Satuni at the Paris observatory, and also first inves- 

 tigated the subject of the zodiacal light, and here, too, the great grand- 

 son of this astronomer was the first to follow the variations of the 

 magnetic needle with minute and persevering industry ; and it was here 

 that Arago aud Mathieu demonstrated the extremely small parallax 

 of the stars. 



A large number of astronomical manuscripts, containing matter of 

 great interest, arc preserved at the Paris observatory, 



II. Observatoire du Bureau des Longitudes. 



(See MoNTSOURis.) 



