
540 EARTHQUAKES. 
in annual catalogues; and Robert Mallet, in England has 
collected similar evidence in his “Catalogue of Recorded 
Earthquakes, from 1606 B.C., to A. D. 1842,” -and has 
done a very important work in his investigation of the great 
Calabrian Earthquake of 1857. With these exceptions, very 
little of importance has been done to investigate the causes 
and seasons and effects of earthquakes ;-and geologists do 
not as yet know whether the shock is caused by the falling 
of huge masses of rock into subterranean caverns, by the 
explosion of gasses pent up in the bowels of the earth, by 
the evolution of steam, when water reaches the heated inte- 
rior of the globe, by the surges and tides of an inner molten 
sea, acted upon by the moon’s attraction or terrestrial revo- 
lution, by the gradual contraction of the -earth’s cooling 
crust, by the waxing and waning of the internal heat locally, 
by some unknown law, or by any of the other causes *° 
ingeniously suggested, most of which are as probable as the 
subterranean convulsions of an imprisoned Titan. 
Catalogue makers have to trust to evidence which has be- 
come more or less distorted in passing through many hands; 
they do not see for themselves. When an earthquake wari 
place, everybody is caught unprepared, and if not killed, 
yet so terribly frightened, as to be wholly unfit to describe 
events exactly as they took place. The evidence of one 
good observer, who examines the ground after it has all 
passed, is of more value than a.score of newspaper reports 
at the time. But our geologists all live far away from p 
quake countries, and only a return to the shakes, which too 
them up t° 
place in New England a century ago, will wake 
the importance of seismic* studies. Let us not feel to 
cure among our granite hills. 
New England has been visited by a number ot eat? 638, 
since the Pilgrims landed in 1620. The first was ipt m 
and twenty years later occurred what is called a 2 
earthquake,” but no descriptions have been preserved. 
* Seismic means relating to earthquakes; from seismòs, aN earthquake: 
0 Sê- 

f earthquakes oe 
great 
Rey ee T ee A 
aye er We 



