XLVIII THE ROYAL SOCIETY OF CANADA 
of knowledge is continually opening up wider and wider fields for investi- 
gation. Less than twenty years ago, the suggestion came from a source 
of some authority that it was possible that the future of physical science 
had no more marvels in store. Since then how many striking discoveries 
have been made, including the Rôntgen rays, radium and atomic dis- 
integrations, discoveries of far-reaching importance on account of their 
bearing upon the fundamental facts of science as well as for the practical 
uses to which they have been applied and for their possibilities for the 
future. 
Perhaps however the doubt of the value of abstract science applies 
to some branches only of science, and does not extend to all. The value 
of the study of physics would probably be admitted, as well as that of 
the minuter forms of life, for this everybody knows has important ap- 
plications in the prevention and cure of human diseases, as well as those 
of animals and plants. Some other sciences, however, may be thought 
to be remote from the practical affairs of life. Let us consider the 
place in science of astronomy, which perhaps is popularly looked upon 
as the most remote of all. 
Astronomy has many very useful applications in navigation, sur- 
veying and the keeping of time; but the principles used in these, it will 
be said, have long since been known. For all such purposes it is sufficient 
to know the places in the sky and the apparent motions of only a very 
few of the celestial bodies, the sun, the moon, some of the brightest of 
the fixed stars, with perhaps some of the planets. With present knowl- 
edge the places of those bodies can be predicted for many years to come 
with all the precision that is needed. Why then multiply observatories, 
when one or two would be sufficient to watch the bodies in question, in 
order to make sure that no error had occurred in the calculations, or 
that no unforeseen displacement had taken place? Why take the 
trouble to find out the chemical constitution of such remote bodies, 
or the motions of the smaller stars, so far away that, though their light 
comes to us at the rate of eleven million miles a minute, we see only 
what has happened scores of years before? 
Astronomy was the first of the sciences to establish itself on the 
basis of general laws. Owing to the wide generality of the laws of mo- 
tion and gravitational attraction, which are laws governing all matter 
on the earth as well as in the sky, they became for all sciences that deal 
with the properties of matter basal principles upon which reasoning 
could be founded, as well as an incentive to investigators to look for 
other general principles. 
The reason that astronomy was able to perform this service was 
that the bodies which it is concerned are so far apart that it was possible 
to consider their motions under their mutual attractions alone, apart 
