Zuch on Repeating Circles. 359 



By the pole-star uppei- culm. 



lower ditto 



By/3 Ursa; Mi?ioris upper ditto 



— lower ditto 



By a Draconis upper ditto 



lower ditto 



By ? Urs<s Majoris up[)er ditto 



lower ditto 



By |3 Tmiri 



By /3 Geminoriim 



M. Mechain was never satisfied with his observations. 

 M. Delambre said of him that lie "was difficult to satisfy ,• but 

 this excellent and scrupulous observer had good reason to be 

 so, for he alone knew what he suppressed ; he knew better 

 than any body those irregularities which caused his despair. 

 He said to all who talked with him on the subject, he wrote 

 to his friends, he wrote even to M. Borda himself, who was 

 then despotic in these operations, that with these circles he 

 could not make observations even passably correct. This was 

 the reason that M. Mechain wished to return to Spain to re- 

 peat his observations with other circles, and even at his own 

 expense. INI. Borda constantly opposed this project ; and 

 M. Delambre even went so far as to congratulate him on having 

 succeeded in prevailing on M. Mechain to renounce all idea 

 of it (p. 563). Being either less difficult, or more complai- 

 sant to M. Borda, he assures him that his latitude of Bar- 

 celona was, of all that had been observed up to that time, the 

 most certain and the most solidly established, with the assist- 

 ance of excelloit instruments. But, we repeat, M. Mechain 

 alone could estimate the excellence of his instruments ; he alone 

 could know the number of abortive observations, and the great 

 number which it was necessary to reject. M. Delambre could 

 not, therefore, be a competent judge of the labours of M. Me- 

 chain, which he knew only by a selection of according obser- 

 vations, without any knowledge of those which were put aside. 

 At Barcelona, M. Mechain observed nearly the same stars 

 as at Montjou}'; he added to their number Capclla, which 

 there passes the meridian within four degrees of the zenith. 

 The greatest dift'erences were 



By the pole-star upper culm. 

 lower ditto 



