Natural Philosophy, '^Adronomy. S81- 
Dr Brinkley of Dublin, entitled, “ On the Quantity of Solar 
Nutation, as affecting the North Polar Distances of the Fixed 
Stars, deduced from Observation, and the Application of this 
determination to confirm the conclusions relative to the Paral- 
laxes of certain Fixed Stars.” 
Those who have examined with care the very admirable pa^ 
pers which Dr Brinkley has published * on the Parallax of 
certain Fixed Stars, can scarcely fail to be convinced, that the 
great discovery of the parallax has been made by that able 
astronomer ; and we are proud to think that this has been ac- 
complished by an English astronomer, and by English instru- 
ments. If any doubts remained upon this subject, the present 
memoir of Dr Brinkley must, we think, entirely remove them. 
It occurred to him that the great number of observations which 
he had made upon particular stars, might be employed to deter- 
mine the solar nutation, v/hich had been deduced only from 
theory, and had never been ascertained by actual observation. 
According to theory, the solar nutation is about 0'\51 in north 
polar distance for all stars ; and as this quantity is less than the 
parallax of certain stars, Dr Brinkley considered, that if it were 
deducible from his observations, such a deduction would not 
only prove the exactness of his observations, but the power of 
his circle to determine . such minute quantities. As the solar 
nutation goes through all its states twice every year,SDr Brinkley 
considers it impossible to suppose, that if any cause should oc- 
casion the instrument to shew deviations explained by parallax 
which did not actually exist, it should not derange the solar nu- 
tation, and cause the result of an investigation of its quantity to 
turn out erroneous. 
By this method of investigation, applied to several stars, Dr 
Brinkley has obtained the most satisfactory results ; and we 
agree with him in thinking, that there cannot remain the small- 
est doubt with any one who examines the processes, that the ob- 
servations have ascertained with considerable exactness the quan- 
tities of parallax of a Lyra, ^ Cygni^ and Arcturus ; — -that the 
parallaxes of y Draconis, and u Ursa Majoris are extremely 
small ; — and that y Draconis is at least seven or eight times 
• See Irish Transactions, vol. xii, ; and Philosophical Transactions, 1818, 
P, 2T5, and 1821, p. 327, 
