XI. Extract of a letter from the Rev. John Brinkley, D. D. F. R. S. Andrew's Professor of Astronomy in the University of Dublin, to the Rev. Nevil Maskelyne, D. D. F. R. S. Astro­nomer Royal, on the annual Parallax of α Lyræ

Abstract

I have now had sufficient experience of my eight feet circle, to be highly satisfied with it, and have arrived at one con­clusion, that it is of importance in astronomy. My observations on α, Lyrae for the purpose of discovering an annual parallax now amount to 47 in number, viz. 22 near opposition, and 25 near conjunction, and the mean of these gives a result of 2,"52 as the parallax of the annual orbit for that star, and I have no doubt that it exceeds 2".