1 8a French National Injlitute. 



need of considerable corrections ; it was vaguely known that 

 thefe corrections had been ordered, but it was not certain 

 that they had been executed. 



C. Prony had the good fortune to meet with a copy of the 

 Opus Pala'tinum, in which the tangents and fecants of the 

 lali degrees were as exact as the reft. The title of the book 

 was augmented by the following- words : recens emendatus a 

 Barhlomao Piti/ce, Silcjio, S:c. The feven laft degrees have 

 been calculated anew, which rendered it necetfary to reprint 

 eighty-fix pages, which may be known by fome differences 

 in the paper and type; the latter being more uSed, and the 

 former lefs beautiful, than in the reft of the volume. C. Pro- 

 ny's memoir contains the formulae neceflary for fixing the 

 quantity of the errors, and tables of comparison, which prove 

 the exactneSs of the corrections of Pitifcus. 



T? igonometrical tables oj Borda, publifhed by Delambre. — t 

 Thefe tables are merely logarithmic. The decimal divifion 

 of the circle for which they have been conftrucled, is, with- 

 out doubt, more convenient than the fexagefimal divifion. 

 The celeftial figris, each confifting of 30 degrees, which di- 

 vide the circumference into twelve parts, while each degree is 

 fubdivided into 60 minutes, and the minute into 60 Seconds, 

 deviate too much from the fimple progrefs of the arithme- 

 tical Syftem, which proceeds invariably by tens, not to give 

 frequent rife to very great inconveniences in practice. 



Hijloire Celejh Fran^oife, This important collection pub- 

 lished by Lajande contains observations or the ftars, made at 

 the military fchool in 1783 by Dagelet ; and observations of 

 every kind, made at Touloufe by C Darquier and Hadan- 

 court in the Space of Seven years, beginning at 1791. But 

 the moft eonfiderable part of this volume is the aftonifhing 

 collection of 50,000 ftars, the fruit of the vigils and afliduous 

 labour of eleven years of Michpl le Francois LaJande, the 

 nephew, happily Seconded for three years by C- Burckhardt. 

 It may readily be conceived how ufeful this labour may be 

 in regard to comets, which in future will not afcend in any 

 part of the heavens without being Surrounded by ftars well 

 known, and by help of which their motion and pofitions 

 may be every moment determined. It is no lefs evident that 

 thefe observations, compared with thole made or which may- 

 be afterwards made at different times by different obl'ervers, 

 will, Sooner or later, give rife to interesting remarks on the 

 changes that take place in the heavens on the new ftars that 

 from time to time appear, and on thoSe which loSe them- 

 selves, or at leaft change their Splendour and light. 



Memoir containing the J'olution of a mechanical problem 

 9 fropojc4 



