4 PRESIDENT’S ADDRESS. 
in the domain of physics, but no physicist can help being interested in 
his mode of presentation, and I may have occasion to refer, in passing, 
to some of the topics with which he dealt. 
And now, eliminating from our purview, as is always necessary, a 
great mass of human activity, and limiting ourselves to a scrutiny on 
the side of pure science alone, let us ask what, in the main, is the 
characteristic of the promising though perturbing period in which we 
live. Different persons would give different answers, but the answer 
I venture to give is—Rapid progress, combined with Fundamental 
scepticism. 
Rapid progress was not characteristic of the latter half of the nine- 
teenth century,—at least not in physics. Fine solid dynamical founda- 
tions were laid, and the edifice of knowledge was consolidated; but 
wholly fresh ground was not being opened up, and totally new 
buildings were not expected. 
‘In many cases the student was led to believe that the main 
facts of nature were all known, that the chances of any great 
discovery being made by experiment were vanishingly small, and 
that therefore the experimentalist’s work consisted in deciding 
between rival theories, or in finding some small residual effect, 
which might add a more or less important detail to the theory.’— 
Schuster. 
With the realisation of predicted ether waves in 1888, the discovery 
of X-rays in 1895, spontaneous radioactivity in 1896, and the isolation 
of the electron in 1898, expectation of further achievement became 
vivid; and novelties, experimental, theoretical, and speculative, have 
been showered upon us ever since this century began. That is why I 
speak of rapid progress. 
Of the progress I shall say little,—there must always be some 
uncertainty as to which particular achievement permanently contri- 
butes to it; but I will speak about the fundamental scepticism. 
Let me hasten to explain that I do not mean the well-worn and 
almost antique theme of Theological scepticism: that controversy is 
practically in abeyance just now. At any rate the major conflict is 
suspended; the forts behind which the enemy has retreated do not 
invite attack; the territory now occupied by him is little more than 
his legitimate province. It is the scientific allies, now, who are waging 
a more or less invigorating conflict among themselves; with Philoso- 
phers joining in. Meanwhile the ancient foe is biding his time and 
hoping that from the struggle something will emerge of benefit to 
himself. Some positions, he feels, were too hastily abandoned and 
may perhaps be retrieved; or, to put it without metaphor, it seems 
possible that a few of the things prematurely denied, because asserted 
