10 SIR ROBERT! §,. BALL, LL.D., ¥-B.8., ON 
THE ORIGIN OF NEW STARS. 
By Prof. Sir Ropert §. Batu, LL.D., F.R.S. 
Mr. PRESIDENT, LADIES AND GENTLEMEN,—The subject of 
the address that I propose to give you is “The Origin of 
New Stars,” and the title was naturally suggested by that 
very remarkable star—the most remarkable of its kind which 
has appeared for three hundred years—at which we all looked 
with such interest in the early months of this year. 
But I am taking the opportunity to refer to the subject 
also in a somewhat wider manner--to speak of those 
processes of change and transformation which we observe 
actually going on at this moment in the universe around us. 
First of all as to what we mean by new stars. We look 
up into the heavens at night and see constellations, and 
history tells us that those constellations were the same in 
the days of Homer, and in the days of Job, practically, as 
they are at present. But we must not imagine that those 
constellations, and those arrangements of stars are eternal; 
for, as Professor Hull tells us, the mountains and other 
features of the earth have been in constant change during 
the course of geological time, though those changes are not 
appreciable in historic times; and in lke manner these 
constellations of the sky are not always the same. It is 
very easy to show that within such a period of time as may 
be comparable with geological periods, the whole face of 
the skies, too, will have undergone a complete transformation. 
We have all seen in museums the ichthyosaurus, the eye of 
which is a most remarkable optical instrument; but if that 
animal could ever have glanced up to the skies I think I 
shall be justified in saying that not a single one of those 
stars that we now see were then within his ken. The 
heavens have gradually changed, and in the course of a 
certain period of time—say ten million years, from what we 
know of the movements of the stars, there would doubtless 
be a complete transformation ; so that the stars which we 
see about us now, that may be unchangeable from our 
ephemeral point of view, are im a state of gradual change. 
When coming down Channel you see a number of ships about ; 
you do not see much motion in them, if you look again, in 
