Notice of Active and Extinct Volcanos. 75 



the surface." (BakewelPs Geology.) We will quote Mr. 

 Bakewell, still further, as to the phenomena of earthquakes. 



"Earthquakes are almost always preceded by an uncommon 

 agitation of the waters of the ocean, and of lakes. Springs send 

 forth torrents of mud, accompanied with a disagreeable stench. 

 The air is generally calm, but the cattle discover much alarm, 

 and seem to be instinctively aware of approaching calamity. A 

 deep rumbling noise, like that of carriages over, a rough pave- 

 ment, — a rushing sound like wind, — or a tremendous explosion 

 like the discharge of artillery, immediately precede the shock, 

 which suddenly heaves the ground upwards, or tosses it from side 

 to side, with violent and successive vibrations. The shock sel- 

 dom lasts longer than a minute ; but it is frequently succeeded by 

 others of greater or less violence, which continue to agitate the 

 surface of the earth for a considerable time. During these shocks, 

 large chasms and openings are made in the ground through which 

 smoke and flames are seen to issue : these sometimes break out 

 where no chasms can be perceived. More frequently stones, or 

 torrents of water, are ejected from these openings. In violent 

 earthquakes the chasms are so extensive that large cities have in 

 a moment sunk down and forever disappeared, leaving a lake of 

 water in the place. Such was the fate of Euphemia in Calabria, 

 in 1638, as described by Kircher, who was approaching the place 

 when the agitation of the ocean obliged him to land at Lopizi- 

 cum : ' Here (says he) scenes of ruin every where . appeared 

 around me;, but my attention was quickly turned from more re- 

 mote to contiguous danger, by a deep rumbling sound, which ev- 

 ery moment grew louder. The place where we stood shook most 

 dreadfully ; after some time, the violent paroxysm ceasing, I 

 stood up, and turning mine eyes to look for Euphemia, saw only 

 a frightful black cloud. We waited till it had passed away, when 

 nothing but a dismal and putrid lake was to be seen where the 

 city once stood.' " 



To account for the extent to which the vibration of the 

 solid substance of the earth will communicate both shocks 

 and sounds, Mons. Gay Lussac (" Annales de Chimie," &c. 

 Tome xxii, page 429,) remarks, that a vibration of the earth 

 is similar to that of the air ; that it is a powerful undulation, 

 produced in the mass of the earth, by some commotion, and 

 that it is propagated, with the same celerity as sound. If we 

 are surprised at the immense extent, to which the shock, the 

 sound, and the ravages of an earthquake are perceived, we 

 may be instructed by considering, that the shock produced 



