j4»d LONGITUDE of ABERDEEN. 



139 



Having the following obfervations of fixed flars re4uced, I 

 have alfo fent them. 



Latitude, 



The declinations of the above flars were taken from M. de 

 LA Lande's catalogue of the declinations of 350 ftars, adapted 

 to the beginning of the year 1790. 



I SHALL conclude by obferving, that the differences in the 

 above latitudes are to be attributed to the error of obfervation, 

 to the inaccuracy of the divifion of the quadrant, and to the un- 

 certainty of the refradlion, efpecially at low altitudes. If the re- 

 fraftion at 45° be affumed a little greater than that by Dr 

 Bradley, the refults will agree much better. It mufl alfo 

 be obferved, that the fmoke of the town will increafe the refrac- 

 tion. 



57 8 isi 



I am^ 



Dear Sir, 



Your obedient fervant, 



Andrew Mackay. 



R2 



LET- 



