118 EARTH FEATURES AND THEIR MEANING 



in the grander eruptions. It is generally possible to distinguish 

 eruptions of at least two orders of intensity greater than the 

 Strombolian phase; a grander one, the examples of which may 

 be separated by centuries, and one or more orders of relatively 

 moderate intensity which recur at intervals perhaps of decades, 

 their time intervals subdividing the larger periods marked off by 

 the eruptions of the first order. 



The eruption of Volcano in 1888. In the Eolian Islands to 

 the north of Sicily was located the mythical forge of Vulcan. 

 From this locality has come our word " volcano," and both the 

 island and the mountain bear no other 

 name to-day (Fig. 113). There is in the 

 structure of the island the record of a, 

 somewhat complex volcanic history, but 

 the form of the large central cinder cone 

 was, according to Scrope, acquired during 

 the eruption of 1786, at which time the 

 crater is reported to have vomited ash for 

 a period of fifteen days. Passing after 

 this eruption into the solfatara condition, 

 with the exception of a light eruption in 

 1873, the volcano remained quiet until 

 1886. So active had been the fumeroles 



Gcate ofMi/es. 



craters partially dissected 

 by the waves belong to 

 Vulcanello (after Judd). 



FIG. 113. Map of Vol- 

 cano in the Eolian group 



of islands. The smaller within the crater during the latter part of 

 fafe pe riod that an extensive plant had 

 been established there for the collection 

 especially of boracic acid. In 1886 occurred 

 a slight eruption, sufficient to clear out the bottom of the crater, 

 though not seriously to disturb the English planter whose vine- 

 yards and fig orchards were in the valley or atrio near the point d 

 upon the map (Fig. 113), nearly a mile from the crater rim. On 

 the 3d of August, 1888, came the opening discharge of an eruption, 

 which, while not of the first order of magnitude, was yet the greatest 

 in more than a century of the mountain's history, and may serve us 

 to illustrate the Vulcanian phase of activity within a cinder cone. 

 During the day, to the accompaniment of explosions of consider- 

 able violence, projectiles fell outside the crater rim and rolled 

 down the steep slopes toward the atrio. These explosions were 

 repeated at intervals of from twenty to thirty minutes, each 



