/ 



THE 



PHILOSOPHICAL MAGAZINE. 



I. Hiftory of AJlronomy for the Year 1800. By Jerome 

 De Lalande *. 



L HP century now clofed has been very remarkable in 

 regard to aflronomy : telefcopes, indeed, and the laws of 

 Kepler and of attra6lion, will place the 17th century at the 

 head of all the reft. Nothing had been before done, and the 

 iirft century, when aftronomers began to labour, ought to be 

 that of difcoveries. But the i8th century has furnifhed us 

 with at leaft twelve epochs fo important that it will bear to 

 be compared with the preceding. A new capital planet and 

 eight fatellites difcovered, the periodical return of comets 

 known and demonftrated, and 68 new comets obfcrved and 

 determined ; the aberration and nutation of the ftars ; the 

 tranfit of Venus, and the true diftance of the fun and of all 

 the planets ; the figure of the earth and its irregularities ; 

 calculations in regard tp the inequalities produced by attrac- 

 tion, and, above all, in regard to Jupiter and Saturn, which 

 have furniflied correal tables of all the planets and their fa- 

 tellites 5 tables of the moon, the moft important of all, car- 

 ried to the precifion of a quarter of a minute ; and, in the 

 laft place, 50,000 ftars accurately obferved : all thcfe far fur- 

 pafs the hopes which could have been conceived a century 

 ago of the progrefs of aftronomy fince that period. To thefe 

 we muft add the improvement of aftronomical inftruments : 

 fctSlors, meridian telefcopes, whole circles, reflecting circles^ 



'* From Magazin Etvyrlopcdique^ No. 17, an. 9. 



A % telefcopes 



No. XXXIII. February 1801, 



