ai8 Hijloty of AJlronomy for the Year i8o2. 



chenaye between the years 5 and 9. The fourth volume 

 of the Memoirs of the InlHtute contains fome alfo. 



C. Coulomb read in the Inftitiite experiments on the me- 

 thod of magnelizing needles to faturalion ; with a compara- 

 tive view of the methods of Knight, Duhamel, and ^pinus. 

 He has pointed out to navigators the fureft means of obtain- 

 ing the beft needles. The broadeft and largeft are preferable, 

 but they niuft not be thick. This philofopher has publifhed 

 in the fourth volume of the Inftitute a curious memoir on 

 the dipping needle. 



The declination of the magnetic needle at Paris was ob- 

 ferved by C. Bouvard at the obfervatorv, on the 2d of May, 

 to be 22'^ 3', and on the 23d of July 21° 45'. 



C. Lenoir, at the Garden of the Depot de la Marine^ 

 found it on the 20th of June to be 22° 6' with a compafs, 

 on which he employed every care poffible. But the changes 

 which take place at the different hours of the day, and in dif- 

 ferent months of the year, amount to more than 10'. We 

 can therefore only fay that the declination is 22", and it was 

 found to be the fame in 1792 and i8co ; fo that at prefent it 

 appears to be ftationary, whereas ten years ago it increafed 

 from 6' to 8' annually. 



Forty years ago T obferved it to be j8_|.°. (See Omnoiffancc 

 des Temps for 1762.) 



M. Simonin, profcfl(3r of Croific, has fent us the refult of 

 a thoufand obfervations on the tides, with the tables necef- 

 fary for keeping an account of the variations produced by the 

 fun and moon according to their altitude and di fiance. 



M. Romme, profelTbr of Rochfort, has fent to the Inftitute 

 obfervations made every three minutes from low water to full 

 moon to make known the irregularities, which are very lin- 

 gular: and a new table of the retardation of the tides, de- 

 duced from an immenfe number of obfervations. 



He has prefented alfo a general table of the tides, the cur- 

 rents, and winds, obferved in all the ftas of the earth ; the 

 publication of which will form an important fupplement to 

 the large Trcatife on the Flux and Reflux of the Sea, which 

 1 publilhed in i78£. 



Mr. Grenier, an officer known by his difcoveries in the 

 Indian feas, has written a confiderable work on the winds 

 and currents in all the feas; with a theory which renders the 

 explanation of thein eafier. He propofes to lay it loon before 

 the public. 



XXXVni. On 



