Hljhry ofAJironomy fir ih Year tSpo. il 



hitherto employed, to be Gonftru<Sletl : Franc^jais-Lalande and 

 Burckhardl have uCed it with great fticcefs during the tw6 laft 

 fuinmer folftices. 



Mechain and Delambre have communicated to lis their 

 obfci-vations, and I now find myrelf in poiTefiion of more 

 than 7.00; the mean refult is, that 5" 8 miift be added to 

 my tables. The mean ior the lird of January 1800, is 

 %f2l 58-. 



• The diminution would be 4!^^ for a century; and taking 

 as^ the term of comparifon the determinations of Bradteyj 

 Mayer, anc^Lacaille, in 1750, I have found 36'^ for a great 

 many other comparifons, particularly the obfcrvations of 

 Richer at Cayenne in 1672, the oldeft made with any degree 

 of corredlnefs. We have therefore reduced to very little the 

 uncertainty of this element, fo neceiTury in regard to the ftars. 

 Due la Chapelle, with a fextant of fix feet, which had been 

 employed by Lacaille, has found 19" lefs than that celebrated 

 aftronomer did in 1750^ being a diminution of 38^^ per 

 century. 



In the Ephemerides of Vienna for 1800 and 1801, Trief- 

 necker has collected all the calculations of eciipfes obferved 

 fince 1747, in order to deduce from them the longitudes of 

 the cities of Europe and Americ^t, and alfo the errors in the 

 tables. Never were fo many eciipfes calculated ; and that 

 able aftronomer has thus rendered a new and very important 

 fervice to government. 



Goudinj who has beftowed great labour on the analytical 

 calculation of eciipfes, and w ho has publifhed feveral memoirs 

 on that fiibje(ft, has by his analyfis completely determined th6 

 circumftances of the eclipfe of 1847, ^^^^ "''^^^^ confiderable of 

 the prefent new century. Duvaucel, to whom we are in- 

 debted for the delineation of eciipfes for thirty years p:ift, ha^ 

 delineated alfo this eclipfe for everv country on the globe : by 

 his diagram it appears that it will be annular in England^ 

 France, Turkey, and even Cochincnina. 



Duvaucel has delineated alfo the eclipfe of the nth of Fe- 

 bruary 1804, which will be curious^ becaufe it will be total and 

 Annular in different countries according to the altitude of the 

 fun : annular at fun-rifing in America,, and at the felling in 



B a, Alia, 



