H'tjlory of AJlronomy for the Year 1800. ^ 



Ilru(Slion of the tables of Delambrc and Von Zach. How- 

 ever this may be, I cledu6l 10'' from the fun's place in cal- 

 culations where great precifion is required. 



Delambre does not admit this correction ; he fays, that in the 

 300 obfcrvations of Greenwich, which he calculated in order 

 to conftruft his tables, he compared the fun with the (lars 

 which palTed in the day-time, one before and the other after 

 the fun; and he adds, that unlefs this precaution is taken, 

 we cannot aflert that 10''^ are to be deducted from his tables. 



An account of the grand labour by Delambre refpe6ling 

 a degree of the meridian between Dunkirk and Rodez, has 

 been printed. The fouthern part, executed by Mechain, 

 will next appear. 



Vidal continues to fend us obfervatlons of the liars below 

 the tropic. Bernier, who laboured with me for nine months 

 before his embarkation, reduced them up to the year 1800; 

 and they will foon be printed. 



Delambre has undertaken to obferve with a whole circle 

 the declinations of the (lars of the ift, 2d, and 3d magni- 

 tude ; which will add a new degree of perfection to the ca- 

 talogue of the principal liars publiOicd annually in the Con- 

 noijfance dcs Temps. 



The defcription of the aftrolabe planifphere, found by 

 Gail in Synelius, has induced Delambre to give a long me 

 moir on the hiltory of aftrolabes, their conitruClion, their 

 properties, and the method of finding new refults even in the 

 nioft hackneyed part of adronomy. 



Burckhardt has found a formula which reprefcnts the de- 

 clinations of the macnietic needle obfcrved at Paris fince the 



o 



year 1580. It appears from this formula that the period of 

 the declination of the magnetic needle is at Paris 860 years ; 

 that the greateft declination weft is 30' 4, and will take place 

 in the year 1878 : the greateft eaftern declination is only 23°. 



The printing of the Hijtoirc ceUfle Fran^aife, which is a 

 colle6lion of all our obfcrvations, is ftill continued. My 

 Bihliographic Ajlronomtque is alfo continued, but the print- 

 ing-oOice of the republic is not fufficient for all the under- 

 takings which have already been begun in it. Chaptal, the 



Vor^ IX. B minifter 



