EARTHQUAKES. 3 
WHAT 15 AN EARTHQUAKE? 
=O 
BY PROFESSOR F. W. HUTTON. 
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What are earthquakes? Where do they come from? How 
are they caused? These are questions which may interest many 
people in New Zealand, although we cannot, at present, see that 
any useful result is likely to follow from an investigation of 
earthquake phenomena. However, on this point no one can 
dogmatize. In no case have the practical results which followed 
from a scientific discovery been foreseen, and, perhaps, in no case 
has an important scientific discovery been made bya person who 
was looking only for practical results. The ancient philosophers 
were ridiculed for poring over the various figures presented when 
a cone was cut in different directions, and yet the practical ap- 
plication of astronomy to navigation was one of the results of 
their studies. The patient investigation of minute forms of life, 
which followed immediately on the invention of the microscope, 
was undertaken without any idea of its being useful; and yet 
nearly all our sanitary arrangements are based on the discovery 
that disease and living germs are intimately connected. The in- 
vention of the steam-engine seems at first sight to be an excep- 
tion; but it is not so, for it was only a practical application of 
the law of the expansion of gases. Watt discovered nothing 
new: but it occurred to him how a very useful combination of 
things already known might be made. It is a mistake to call 
the invention of the steam-engine a scientific discovery ; a his- 
tory of science might, and should, pass it by unnoticed, but it 
forms a very important era in the history of industrial art. We 
certainly cannot expect to be able to prevent earthquakes, but 
neither can we prevent storms; yet every civilised Government 
spends money in the investigation of meteorological phenomena, 
with the hope that it may be possible to foretell the weather. 
And would it not be as useful to be able to foretell earthquakes? 
And is it impossible to do this? He would indeed be but a half- 
hearted philosopher who could harbour such a thought for an 
instant. 
But, to return to the question at the head of the paper, 
“What is an earthquake ?”? When a heavily-laden waggon jum- 
bles along a rough street, the room of the house we sit in shakes. 
A tremor has been communicated from the wheels of the waggon 
to the walls of the house. An earthquake has happened; none 
the less a true earthquake because it has originated, as we say, 
