Cliap. 82.] 
CLErTS OE THE EAETH. 
113 
down, and in others swallowed up by a deep cleft ^ ; some- 
times great masses of earth are heaped up, and rivers forced 
out, sometimes even flame and hot springs^, and at others 
the course of rivers is turned. A terrible noise precedes 
and accompanies the shock^ ; sometimes a murmuring, like 
the lowing of cattle, or like human voices, or the clashing of 
arms. This depends on the substance which receives the 
sound, and the shape of the caverns or crevices through 
which it issues ; it being more shrill from a narrow opening, 
more hoarse from one that is curved, producing a loud rever- 
beration from hard bodies, a sound like a boiling fluid'* from 
moist substances, fluctuating in stagnant water, and roaring 
when forced against solid bodies. There is, therefore, often 
the sound without any motion. Nor is it a simple motion, 
but one that is tremulous and vibratory. The cleft some- 
times remains, displaying what it has swallowed up ; some- 
times concealing it, the mouth being closed and the soil 
being brought over it, so that no vestige is left ; the city 
being, as it were, devoured, and the tract of country engulfed. 
Maritime districts are more especially subject to shocks. 
!Nor are mountainous tracts exempt from them ; I have found, 
by my inquiries, that the Alps and the Apennines are fre- 
quently shaken. The shocks happen more frequently in the 
autumn and in the spring, as is the case also with thunder* 
There are seldom shocks in Graul and in Egypt ; in the latter 
it depends on the prevalence of summer, in th® former, of 
winter. They also happen more frequently in the night than 
in the day. The greatest shocks are in the morning and the 
evening ; but they often take place at day-break, and some- 
times at noon. They also take place during eclipses of the 
sun and of the moon, because at that time storms are lulled. 
They are most frequent when great heat succeeds to showers, 
or showers succeed to great heat^. 
^ Poinsinet enters into a long detail of some of the most remarkable 
earthquakes that have occurred, from the age of Pliny to the period when 
he wrote, about fifty years ago ; i. 249. 2. 2 ^qq Aristotle, Meteor, ii. 8. 
3 See Aristotle, Meteor, ii. 8, and Seneca, Nat. Qusest. vi. 13. 
4 "I'ervente;" " Premitum aquse ferventis imitante." Alexandre in 
Lemaire, i. 404. 
^ The reader wiH scarcely require to be informed, that many of the 
remarks in the latter part of this chapter are incorrect. Our author has 
principally followed Aristotle, whose treatise on meteorology, although 
abounding in curious details, is perhaps one of the least correct of his works. 
VOL. I. I 
