45. 



ADDRESS ON PRESENTING THE GOLD MEDAL OF THE ROYAL ASTRO- 

 NOMICAL SOCIETY TO PROFESSOR H. D' ARREST. 



[From the Monthly Notices of the Royal Astronomical Society, Vol. xxxv. (1875).] 



IT has been already announced to you that the Council have awarded 

 the Society's Medal to Professor H. L. D'Arrest, Director of the Observatory 

 of Copenhagen, for his Observations of Nebulae contained in his Resultate 

 aus Beobachtungen der Nebelflecken und Sternhaufen and in his later and 

 much more extensive work, Siderum Nebulosorum Observations Havnienses, as 

 well as for his other recent astronomical labours. It now becomes my duty 

 to lay before you the grounds of this award ; and I feel confident that a 

 plain statement of the nature and extent of the work accomplished by 

 Professor D'Arrest will be sufficient to convince you that he richly deserves 

 our medal. 



Professor D'Arrest has been long well known for his contributions to 

 our science. No reader of the Astronomische Nachrichten can fail to have 

 been struck by the untiring activity shewn by his numerous communications 

 to that periodical, so indispensable to the astronomers of all countries. 

 Among his discoveries I may refer to that of the interesting periodical 

 comet which bears his name, and likewise to that of the minor planet 

 Freia, the 76th member of the group of small planets between Mars and 

 Jupiter, the known number of which now amounts to 142, and is yearly 

 increasing at a rate which shews no signs of slackening. 



But of all the labours of Professor D'Arrest, unquestionably the most 

 important are his observations of nebulae contained in the two works men- 

 tioned at the commencement of this address. 



