SCIENTIFIC NEWS. 



XI. 



SI? 



ExlraSi of a Letter from the Rtv. John Brinkley, D. D, 

 F, R.S. Andrews Professor of Astronomy in the University 

 0f Dublin, to the Rev. Neyil Maskelyne, D.i). F.R.S^ 

 Astronomer Royal, on the annual Para/lax qf» Lyrce, 



JL 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 « Lyrae for the purpose of discovering Annua! paral. 

 an annual parallax now amount to 47 in number, viz. 22 '^''^■®^ •^F'^ 

 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'. 



My observations of different circumpolar stars, and of the Qj. Bradiev^? 

 same star indifferent states of the thermometer, seem to formula for 

 require a small alteration in the numbers of Dr. Bradley^ refraction 

 formula for refraction. 



The formula so altered is — Refraction ~ 5<)'9' X altered 



S r, J- « ^ -D r 7 ^ heightofbarom. 500 



tang. -! Zen. dis. — 3'2 Refr. > X — x : 



''I 3 29-6 '^450+-ther. 



By means of this formula, the observations of circumpolar 



stars considerably distant give the same colatitude to a 



great degree of exactness. 



SCIENTIFIC NEWS. 



T the meetinff of the Wernerian Natural History Soci- .„ 



Wernenau s©- 

 ety, at Edinbur|(;;h, on the 12th of January last. Professor ciety. 



Jameson read the firit part of a series of observations on the 

 g^eognostic relations of the rocks in the island of Arran. In q - 



this memoir he described particularly the granite, gneiss, Arran. 

 mica-slate, and ciaV'Slate formations, and also the red sand- 

 stone and porphyry-slate, which occur so abundantly in that 

 island. When describing the granite, he stated, as a con*> 



jecture 



