lioyal Astronomical Society. 139 



though in such delicate researches difficulties and anomalies are 

 pretty sure to present themselves. So far as he is able he will 

 tread in Mr. Baily's steps, faithfully recording everything as it pre- 

 sents itself, without hypothesis, and having recourse to every avail- 

 able source of information. The Fellows of this Society, well-aware 

 as they are of the perfect familiarity with every class of instrumental 

 means which Mr. Sheepshanks possesses, will look upon his labours 

 as they proceed with no ordinary interest. 



The circumstances relating to the discovery of the planet Astrsea 

 were detailed in the last number of the Society's Monthly Notices, 

 and it will therefore be unnecessary to detain the meeting by any 

 lengthened remarks on the subject. When the planet was first ob- 

 served in this country it shone with the brilliancy of a star of be- 

 tween the 9th and 10th magnitudes. At the end of December a 

 very material decrease in its brightness had occurred, and at the 

 commencement of the present month the planet could hardly be 

 reckoned brighter than the 11th magnitude. There is a hazy, ill- 

 defined appearance about Astraea, which makes it a matter of no 

 great difficulty to distinguish her, even should there be several small 

 stars in the field with her. Professor Encke was the first to calcu- 

 late the elements of the new planet ; his second elements were mar- 

 vellously exact, though based on observations extending over thir- 

 teen days only. There is a very near agreement in the results of 

 different astronomers, which shows that we have already closely ap- 

 proximated to the orbit of the planet. 



In duly acknowledging the service rendered to astronomy by this 

 discovery, we must not forget that we owe much to the exertions of 

 Professor Encke, who detected the planet again on the 14th of De- 

 cember, and observed it very carefully at every opportunity. On 

 these observations is based M. d' Arrest's excellent Ephemeris, which 

 has been- of great assistance to astronomers during the past month. 

 Since the last Anniversary of the Society three comets have been 

 discovered, and the periodical comets of Encke and Biela have re- 

 turned agreeably to prediction. 



Father de Vico, director of the Observatory at Rome, and one of 

 the Associates of the Society, detected a telescopic comet on the 

 night of February 26, 1845. It did not become visible to the naked 

 eye, and was not observed after the end of April. 



At the beginning of June a fine comet made its appearance in the 

 constellation Perseus. It was followed by astronomers until the end 

 of the month, when it was lost in the twilight. There is strong 

 evidence in favour of the identity of this comet with that of 1596, 

 observed by Tycho Brahe ; an elliptical orbit of 249 years' period 

 satisfies the observations very well. Father de Vico saw Encke's 

 cornet on two days in the month of July, but it does not appear that 

 other astronomers were so fortunate. 



The comet of Biela was found at Berlin with the great Fraunhofer 

 refractor on Nov. 29, and at Cambridge, by Professor Challis on 

 Dec. 1 . At this time it was excessively faint, but the agreement 

 between the observed places and the positions given by Santini's 



