lxxviii President's Address 



the establishment of a great reflector, and there is every 

 ground for confidence that this will not long form an 

 exception. 



Whatever reasons could be assigned for it in 1856, still 

 weightier reasons exist now. From the experience acquired 

 in England during that time, the construction of a telescope 

 of the kind required a reflector of four feet aperture, has 

 become a matter of mechanical certainty, and no longer an 

 experiment with a great risk of failure. 



Lord Rosse also reports that on comparing his earlier 

 drawings with those made at a later period, he has observed 

 in some of the nebulae systematic changes of form. If this 

 is really so, and there seems no ground for doubting it, what 

 a vast field for speculation and research is opened out by 

 it ; that we should be able to look at other systems, grander 

 and more complicated, perhaps, even than our own firma- 

 ment, but placed at such a distance that we can see them as 

 a whole ; that we should be able to watch in them gradual 

 changes which we can only infer in our own from laborious 

 observation of details, is indeed a triumph the achievement 

 of which is worthy of our best efforts. 



In 1862, Sir Henry Barkly forwarded to the Duke of 

 Newcastle a series of resolutions passed by the Board of 

 Visitors at Melbourne, requesting the advice of the Boyal 

 Society of London, and the British Association, as to the 

 best form of telescope. 



In his annual address to the Boyal Society in December 

 that year, General Sabine, the President, after announcing 

 this, added — 



" I cannot close this brief notice without congratulating 

 the Society on the prospect thus opened, of accomplishing 

 an object Of such manifest importance, as to have induced 

 the Boyal Society and the British Association to solicit 

 jointly the aid of Her Majesty's Government in effecting it ; 



