VOL. LXXVI.] PHILOSOPHICAL THANSACTIONS. 83 



VIII. Observations on the Sulphur IVells at Harrogate, made in July and Aug. 

 1785. By the Right Rev. Rich. Lord Bishop of Landaff, F. R.S. p. 17 I . 



Reprinted in the 5th vol. of the Bishop of LandafTs (Dr. Watson's) Chemical 



Essays. 



IX. Observations and Remarks on those Stars which the Astronomers of the last 

 Century suspected to be Changeable. By Edw. Pigott, Esq. p. ISQ. 



It is about a century since Hevelius, Montanari, Flamsteed, Maraldi, and 

 Cassini, noticed a certain number of stars which they supposed had either dis- 

 appeared, changed in brightness, or were new ones; and yet to this day we have 

 acquired no further knowledge of them. This may be attributed to the difficulty 

 of finding out what star is meant, and the not having exact observations of their 

 relative brightness. I therefore have drawn up the following catalogue, and 

 made the necessary observations; so that in future we can examine them without 

 much trouble, and be certain of any change that may take place. To accom-. 

 plish this, it was requisite to compare with attention many authors and most of 

 the catalogues of stars; in doing which, I have perceived several undoubted 

 errors, and others highly probable. 



In order to separate certainty from doubt, I have classed these stars in 2 divi- 

 sions; the first are undoubtedly changeable; the others remain yet to be better 

 authenticated. Though some of them bear all the appearance of being variable, 

 still no certainty of their being so has come to my knowledge. To those of the 

 first class are subjoined observations made on them within these last 4 years, 

 from which the period and progressive changes of some are deduced, though 

 never settled before; and if already known, are more exactly determined by com- 

 paring my observations with former ones. Also, as the position of several are 

 determined only by ancient astronomers, and therefore inaccurately, I have ob- 

 served them with great exactness, the declinations being taken with a Bird's 18- 

 inch quadrant, and the right ascensions with a 3-feet transit instrument; these 

 last may serve in future to discover their proper motions in right ascension, for 

 which reason I shall specify the stars to which they were compared. The stars 

 of the 2d class have either their relative brightness exactly settled, or their non- 

 existence ascertained. I have also pointed out the probability of a mistake in 

 several, and in general given an account of the appearance they have had within 

 these few years. 



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