102 



PHILOSOPHICAL TRANSACTIONS. 



I 



a 



S. Willow 1756 



1765 



G. Alder, in sandy soil 1 759 



1776 

 S. Asp 1772 



1781 

 G. Mountain ash 1759 



1781 

 G. Birch 1759 



1768 

 G. Horse-chesnut 1758 



1779 

 G. Lime, in sandy soil 1777 



1783 

 G. Cedar, one foot high in 1748 1777 



1795 

 G. Silver fir, planted in 1746 1758 



1781 

 G. Scotch fir, planted in 1735 1756 



1781 

 G. Spruce fir, planted 1735 1 755" 



1781 

 S. Weymouth pine, planted in 1747 T756 



1781 

 G. Pinaster, planted in 1738 1756 



1762 

 G. Larch, planted 1749 1758 



1781 

 S. Holly, from seed, by me, and transplanted 1749 



1781 

 S. Hawthorn, by Hethel church, Norfolk, at 4 ft 1755 



1781 



VI. On the Periodical Changes of Brightness of Two Fixed Stars. By Edward 



Pigott, Esq. p. 133. 



The discoveries which at present I have the honour of laying before the r. s. are 

 the periodical changes of brightness of 2 stars, one in Sobieski's Shield, the other 

 in the Northern Crown. The constellation of Sobieski's Shield consists of a very 

 few stars, and was formed by Hevelius, in honour of a king of Poland ; the varia- 

 ble star that now appears in it was doubtless not noticed by him, as he has set down 

 stars near it, which are by times much less conspicuous. It has nearly the same 

 right ascension as the star /, and is about 1° more south. When at its full and 

 least brightness, it attains in' different periods, different degrees of brightness : I 

 have never yet seen it of a greater magnitude than of the 5th, nor when at its least ) 

 less than the 7.8th. It completes all its changes in about 63 days, being 14 + at 

 its full brightness, without any perceptible change ; 9 ± at its least, also without 



