Physical Science in the Time of Nero: Naturales Quaestiones (1910) - Page 23

CHAP.		PAGE
XIII.	Aristotle and Theophrastus consider evaporation to be the cause. Strato, in much the same way, thinks differences in internal temperature are the cause .	240
XIV.	Some think air is the cause, but that its operation, along with water, is like that of blood and air in the vessels of the body. The earth, it is assumed, admits air, which must find an exit. When it does so violently, the result is an earthquake	242
XV.	The earth is porous and perforated at many points, which is how the air enters .	243
XVI.	The earth is full of air, which nourishes plants rooted in it and exhales enough to feed the sun and the other heavenly bodies. Air is the most movable of elements; therefore, if the earth is full of air, it must also experience frequent movements	244
XVII.	Obstruction of air, just like water, causes greater impetuosity when it finally escapes. Wind is frequently associated with earthquakes, as at Chalcis .	245
XVIII.	Additional considerations to prove that the great cause of earthquakes is air, i.e., wind .	247
XIX.	Metrodorus of Chios compares the rumbling of an earthquake to the resonance of a voice in a tub; underground caves provide the sound .	248
XX.	Various combinations of water and air are supposed by Democritus and Epicurus to cooperate in the production of earthquakes .	249
XXI.	Air must be the cause. Different kinds of earthquakes .	251
XXII.	First species: the shaking of the earth; its causes .	252
XXIII.	Next comes the form of concussion caused by air. The great Callisthenes, who braved the fury of Alexander and lost his life for it, supports this view. Submarine effects of it are particularly noticeable .	253
XXIV.	Different explanations can be given of the exact method in which air acts .	255
XXV.	The striving of air in subterranean caverns produces a concussion or collapse in the earth above. The area of disturbance is limited, never exceeding 200 miles, as numerous instances prove. The Peneus and Ladon rivers were formed this way .	256
XXVI.	The nature of soil composed of muddy accretions without gaps is said to account for why Egypt is exempt from earthquakes. So, too, Delos in the sea has porous rocks that emit air easily. But the facts are wrong; there is abundant proof that proximity to the sea is no safeguard against shock .	258
XXVII.	A peculiarity of the Campanian earthquake, that it killed 600 sheep, is explained by the emission of pestilential vapor, by which sheep, with their heads close to the ground, were naturally most easily affected .	259
XXVIII.	Noxious vapors are not, however, peculiar to earthquakes. They are found in several parts of Italy habitually. Such, too, is the origin of new diseases .	261
XXIX.	Excessive fear drives people mad. Earthquakes split statues and divide kingdoms, for example, Sicily from Italy, and Spain from Africa .	262