Zach <5« Repeating Circles. 361 



The 5i/ir Metrique had not then appeared ; all the irregula- 

 rities of which we have been speaking, and all the mortifications 

 which these instruments had caused the French astronomers, 

 wex'e therefore unknown. We were at that time occupied in ob- 

 serving the latitude at the observatory of Seebeig, with a circle 

 exactly similar to those with which MM. Delambre and Me- 

 chain were labouring at the great meridian of France. These 

 observations will be found registered in the 9th volume, p. 292, 

 of our Cor7esj}o?idance Astionomique Allemande., and it will there 

 be seen, that the greatest differences we had in the latitudes 

 served by us, were the following : 



By the pole-star upper culm. 



lower ditto 



By a Aquilce 

 By the Sun 



With this same circle we observed the latitude of Mont 

 Brocken. These observations are to be found in the 10th volume, 

 p. 203, of the Corresp. Allemande. The greatest differences were 



Greatest DifT. NumI). of Obs. 



By the Sun .... 4,"0 340 



By a Aquilce . . . . 3, 6 188 



It appears by these experiments, that the anomalies which 

 we found with these circles of Lenoir, were very nearly the same 

 as those which the Parisian astronomers had encountered ; 

 they were rather less considerable than those remarked by 

 M. Delambre, and equal to those experienced by M. Mechain 

 at Barcelona ; with this difference, that we have not withheld 

 any of our observations, whilst M. Mechain rejected his by 

 thousands, and selected such only as agreed the best. 



In 1807 we were at Munich, where we became acquainted 

 with the repeating circles of Reichenbach. With one of these 

 circles of twelve inches diameter, we made our first essay on 

 that instrument in the garden of M. Utzschneider, and we had 

 the following differences : 



Greatest Diflf. Numb, of Obs. 

 By the Sun ... . 1,"75 574 



By a Aquilce . . . . 0, 83 140 



In 1802, the French geographical engineers had made a 



freat triangulation in Bavaria with the repeating circles of 

 ,enoir. M. Henry, at the same time, made 352 observations 

 of latitude in the northern tower of Notre Dame. We went 

 to the same tower with the circle of Reichenbach, and we there 

 made nearly the same number of observations, which gave us 



Greatest Dill'. Numb, of Obs. 

 By the Sun .... 1,"37 358 



Vol.61. No. 301. May 1823. Z z In 



