GREEK IDEAS OF VULCANISM. 559 



fluence of Posidouius, certainly one of the most intelligent travelers 

 of antiquity, upon writers in all departments of science is particularly 

 marked. Strabo has preserved for us his observations in connection 

 with Etna eruptions, with the elevation of volcanic islands, with earth- 

 quakes which happened in Phoenicia, and with a great variety of phe- 

 nomena, sometimes in considerable detail, and in terms which agree 

 closely with those of modern experience. The following graphic de- 

 scription of the formation of a new volcanic orifice amongst the Lipari 

 Islands may suffice for an example : 



Posidonius says, that at a time so recent as to be almost within his recol- 

 lection, about the summer solstice and at break of day, between Hiera and 

 Euonymus, the sea was observed to rise suddenly to an extraordinary height, 

 and to abide some time raised in a compact mass and then to subside. Some 

 ventured to approach that part in their ships; they observed the fish dead and 

 carried by the current, but being distressed by the heat and foul smell, were 

 compelled to turn back. One of the boats which had approached nearest lost 

 some of her crew, and was scarcely able to reach Lipari with the rest, the men 

 being stricken like epileptic persons, at one time fainting and giddy, and at 

 another returning to their senses. Several days afterwards a mud or clay 

 was observed rising in the sea, and at many points the flames issued, with 

 exhalations and smoke; after a time the scum congealed and assumed the ap- 

 pearance of millstone.* 



Accounts of the upheaval and disappearance of volcanic islands in 

 the Mediterranean are by no means rare in classic literature, probably 

 the best known example being that already alluded to in connection 

 with Thera in the year 197 B.C. On this occasion, a number of reports 

 tell us, flames rose from the water for four days between Thera and the 

 neighboring Therasia, so that the whole sea boiled and blazed; and 

 little by little an island was ejected, being lifted as it were by me- 

 chanical force, and composed of volcanic rock extending over an area 

 of twelve stadia in circumference. It is now generally admitted that 

 the Santorin group is the basal wreck of a very large and ancient vol- 

 canic mountain, the eruptive history of which is comparatively well 

 known. Prior to the sharp outbreak which occurred in 1866, memo- 

 rable in geological annals, it was supposed that the eruption of 197 

 B.C. was the earliest which can be associated with the period of its 

 human occupancy. Shortly after the last outbreak, however, relics 

 of an ancient civilization were discovered in the islands of Thera and 

 Therasia, buried beneath a layer of pumice-stone and other volcanic 

 debris. As to the period of culture indicated by these remains, archeol- 

 ogists are agreed in referring them to the Proto-Mycensean, which is 

 supposed to antedate our present era by at least 2,000 years. 



Eloquent testimony exists in classic literature that men were pro- 

 foundly impressed even in earliest times by the class of phenomena 

 typified by Thera and the mythical Atlantis. From the rise and dis- 



* Strabo, VI., 2, 11. Compare also the similar accounts given by Pliny 

 ('Nat. Hist.,' II., 19) and Aristotle ('Meteor.,' II., S, 19). 



