The Eruptions at Santorin. 143 



crater, at least so far that they have never raised by its side 

 any other mound approaching in height and extent to the 

 great cone, we find, in the Gulf of Santorin, each separate 

 revival of volcanic action, characterized by its separate and 

 special formation, which we can trace as such even under water 

 down to a common base. These formations owe their origin to 

 a slow emission of large masses of lava quietly overflowing at 

 their point of issue, filling up the irregularities of the bed of 

 the sea, and rising by degrees as islands above the water-level. 

 The eruptions of Mount Vesuvius, on the contrary, are mostly 

 distinguished by a totally different character, inasmuch as the 

 melted rock, flowing from a higher or lower point of eruption 

 down the slope of the mountain cone, spreads in long but 

 narrow streams." 



An interesting peculiarity of the volcanic action at Santorin 

 is the fight which the volcanic fires have had with the cold 

 water of the sea. " The quantity of steam sent forth at 

 intervals of but a few minutes was so considerable, that it often 

 rose to a column of more than 2000 metres in height."* This 

 magnificent display lasted for months, and acting upon the 

 tough, viscid lava, assisted to produce the crater forms. 



On the 16th of May, 1866, without previous symptoms of 

 disturbance, two small islands appeared in the Kaimeni group. 

 " No signs of anything occurring at the bottom of the sea had 

 preceded this event, except that new soundings showed a depth 

 less than that which had been previously observed in the 

 channel." The new islands, which looked like large heaps of 

 black rock, increased from day to day, moving at the same 

 time horizontally from north-west to south-east, as shown by 

 accurate geometrical measurements. In April, the progress 

 of the field of lava of Aphroessaf was principally in a 

 northerly direction, menacing thus to block up entirely the 

 small harbour of St. George. In the beginning of May it 

 became every day more apparent that the mass of lava had 

 changed the direction of its onward movement, taking its 

 course now to the south-west, in the direction of Palea 

 Kaimeni." By the 30th of May the new islands had increased 

 to four, and they represented the emergent portions of the 

 lava currents, which had filled a deep sea-trough between Nea 

 and Palea Kaimeni. 



The displacement of the May islands is highly curious. 

 Our authors describe them as made up of wildly accumulated 

 and brittle blocks, and they regard their onward movement as 

 indicating " not only a greater extension of the igneous mass 

 at the bottom of the sea, but also a displacement and destruc- 



* Rather more than 2187 yards/ or exceeding a mile aad a quarter, 

 t The name of a part of one of the islands. 



