Astronomical and Nautical Collections. 367 



We find in the Transactions for 1814, a continuation of Mr. 

 Groombridge's researches extended to the refraction of stars near 

 the horizon. He observed, that the results, corrected according to 

 the indications of the thermometer without, are the most correct ; 

 he alters the thermometrical factor from .0021 to .002, and adopts 

 finally the expression r =: 5%." 132967 x ta {Z.D — 3.6342956r), 

 reducing it, below 87°, .00462 for each minute. 



Dr. Brinkley, in 1810, had acquiesced in the formula of 

 Simpson and Bradley, with a slight modification, and with the 

 French correction for temperature, that is r = 56".9 ta (Z. D — 



3 . 2;) -i . ^^^ . (Ph. tr. P. 204.) 

 29.6 450 + F ^ 



Dr. Brinkley has pursued the subject with his accustomed accu- 

 racy in the Irish Transactions for 1815, and has employed 65 ob- 

 servations of Capella and 42 of Lyra, together with a multitude of 

 others, confirming the accuracy of the French Tables, He has 

 shown the agreement of several assumed hypotheses, in moderate 

 zenith distances. Thus, at 50° F. and 29.6 B. 



Alt- Obi. Fr. T. 



