3^ Hi/lory of Ajlronomy for the Year 1799. 



The Inftitute decreed, on the 2d of December, that the 

 Minifter for Foreign Affairs {liould be requefted to borrow 

 at Leyden the manufcript of Ibn Tunis, in order that the 

 Arabic text might be printed ; and we have reafon to believe 

 that this reqiieft will be granted. 



C. Bouvard has calculated the Greek and Arabic eclipfes, 

 and found that 3' 13" muft be added to the anomalv, 8' 30''' 

 to the fecular movement of the anomaly of the moon, and a 

 minute to the fupplement of the node for 1790, and that its 

 fecular movement muft be diminifhcd 2' 48"'. 



C. Laplace has determined by theory two equations of the 

 moon. Two long memoirs, tranfmittcd to the Inftitute in 

 confequence of the prize we propofed, contain many obfcrv- 

 ations and calculations on the fame fubjeft. This -part of oui- 

 tables, therefore, fo interefiing to navigation, has acquired 

 this year a new degree of perfeftion. 



On the 8th of May we obfcrved, for the 17th time, the 

 tranfit of Mercury over the Sun's diik. It is the firft ever 

 completely obferved at the defcending node, and there will 

 not be another of the fame kind till the expiration of thirty- 

 two years. It was impatiently expeftcd by all the aftrono- 

 mers. It was obferved throughout all Europe; and C. De- 

 lanibre has drawn up a work, with new formulae, in order to 

 deduce from the tranfits of Mercury all the confequences 

 t;hence refulting. 



C. Vidal, our real Hermophilus, has made at Mirepoix a 

 new feries of obfervations of Mercury in all parts of his 

 orbit; fo that we want nothing more in regard to this pla- 

 net, fo difficult to be fcen ii"^ our climates. This aftonifliing 

 obferver l;as fent us obfervations alfo of more than a thoufand 

 auftral ftars, which can fcarcely be feen at Paris on account 

 oftheir fmall elevation. 



The Ephemerides of Milan for 1799 have furniflied us 

 with a new feries of obfervations of Mercury by C. Cefaris. 

 In thefe I have the pleafure of finding that the errors of my 

 tables are almoft infjjnfible. I have had the fame fatisfac- 

 tion in regard to the digreffiou of Mercury in his aphelion 

 on the lathaf Aiiguft. The diftance of the fun, and the 



eccentricuv 



