GEOLOGY. 267 





causing certain portions to fall below the general level, openin 

 rents at the boundaries, and forcing up molten matter to the sur- 

 face, satisfies the known condition of volcanoes better than any 

 other. 



VOLCANO OF SANTORIN. 



This volcano, described in the ** Annual of Scientific Discovery" 

 for 1866-67, p. 266, has lost none of its intensity during the more 

 than 2 years of its existence. Detonations and explosions every 

 4 or 5 minutes occur, with the ejection of many incandescent rocks 

 and large quantities of ashes, the latter sometimes containing red 

 particles, probably oxide of iron. The smoke from George Inland 

 is always very abundant, forming a column often 4,000 or 5,000 

 feet high. Flames are also abundant around its summit. Occa- 

 sional minor explosions occur at other points, even at the bottom 

 of the sea, with considerable development of smoke and flame. 

 George Island is constantly growing, its top, covered always with 

 scoriaceous and glowing lava, having attained a height of 420 

 feet. The new surfaces present to-day an area of about 1,000,000 

 square metres. Estimating the mean depth of the sea here at 93 

 metres, and the mean height of the surface above the sea at 32 

 metres, we should have a mass of 135 million cubic metres, without 

 reckoning the large amount of lava which has fl.owed beneath the 

 sea, as the present result of the eruption. 



THE GREAT EARTHQUAKE IN SOUTH AMERICA. 



The recent terrible earthquake in South America seems to have 

 ranged from Port Conception, on the southern coast of Chili, to 

 Quito, the capital of Ecuador, just below the equator. It must 

 be classed among the most terrible convulsions of the kind ever 

 known on the American continent, the only parallel to it being the 

 earthquake in February, 1797, when the whole country between 

 Santa Fe and Panama was destroyed and 40,000 people buried in 

 an instant. 



The destruction of Arequipa, a city numbering 119,000 inhabi- 

 tants, was, save the destruction of Arica, and Iquique on the 

 coast, the most appalling scene presented by the earthquake in 

 Peru. It is thus described by an eye-witness : — 



•* About 4 minutes past 5 p. m., last Thursday, the 13th of Au- 

 gust, a slight movement of the earth was noticeable here by per- 

 sons who chanced to be seated ; there was no rumbling. In about 

 8 to 10 seconds more, the movement became strons: enoujrh 

 for persons not seated to notice. This movement gradually in- 

 creased in strength until, after about 30 seconds, pieces of tim- 

 ber began to fall from the houses. In about a minute all were 

 satisfied that a great earthquake was at hand. Tlien began a ter- 

 rible rumbling, similar to the noise of an avalanche ; every one 

 ran to the open spaces. It seemed as if the earth was about to 



