1869.] 



President's Address. 



105 



and preceding the lemniscate, whose edges are so bright that if it had 

 then existed it could not have been overlooked in the 20-foot reflector. 

 Another feature, which, however, was perhaps not within reach of that 

 telescope, is an oval which M. Le Sueur describes as " full of complicated 

 dark markings and pretty bright nebular filaments." The angular mag- 

 nitude of the changes which have been thus observed is so great as to 

 suggest a strong probability that this nebula is much nearer to us than 

 the stars which are seen along with it. It may be also noticed that M. 

 Le Sueur saw nothing to make him believe in any development of stars 

 in addition to those seen by Sir J. F. W. Herschel. 



The spectroscope and photographic apparatus belonging to the instru- 

 ment have by this time reached Melbourne, and will no doubt give good 

 results, subject to the condition that the fascination of their use shall not 

 be permitted to interfere with the primary destination of the telescope, viz. 

 the observation of nebulae. 



Celestial spectroscopy has indeed attained such importance, that it 

 requires for its successful prosecution the undivided attention of the astro- 

 nomer who devotes himself to it, as well as an observatory specially designed 

 for it. Our great national observatories cannot supply this want, for they 

 have their own specific destination ; and the high optical power which is 

 required, if we wish to make further progress, is scarcely within the reach 

 of amateurs. 



These considerations have induced your Council to believe that an 

 attempt to encourage and aid this most interesting class of researches is an 

 object in full unison with the highest purpose of the Royal Society's exist- 

 ence ; and they have therefore, after most careful deliberation, resolved to 

 act on this conviction by providing a telescope of the highest power that is 

 conveniently available for spectroscopy and its kindred inquiries. The 

 instrument will, of course, be the property of the Society, and will be 

 intrusted to such persons as, in their opinion, are the most likely to use it 

 to the best advantage for the extension of this branch of science ; and, in 

 the first instance, there can be but one opinion that the person so selected 

 should be Mr. Huggins. 



The execution of this project was much facilitated by the receipt of 

 £ 1350 from a bequest made to the Society by the late Mr. Oliveira; and 

 in the beginning of the year proposals were received from the chief opticians 

 of the time, of which that of Mr. Grubb was accepted last April. 



The conditions proposed were, that the object-glass of the telescope 

 should be of 15 inches aperture, and not more than 15 feet focus, that 

 the arrangements of its equatorial should be such that it could be easily 

 worked by the observer without an assistant, and that the readings of its 

 circles could be made without leaving the floor of the observatory. Mr. 

 Grubb was fortunate enough to secure two disks which had been exhibited 

 by Messrs. Chance at the French Exhibition. They are of first-rate 

 transparency ; and as the construction which has been adopted admits of 



