STROMBOLl 267 



The last and earliest illustration of Stroniboli that I have found, plate 

 9, from Hamilton/s large and classic work/^ represents the island in 

 1768. Here the Zolfo, Sciarra, and Torreone vents in full activity are 

 clearly shown, at the upper edge of the Sciarra, and a fourth farther 

 back, about in the center of the terrace. The text accompanying the 

 plate mentions lava streams flowing from the crater and from the "^^spots'^ 

 marked 2, near the west end of the island. 



To the above illustrational evidence might have been added the many 

 photographs by Tempest Anderson, Lacroix, Perret, Platania, and 

 others — taken either from above or from the northwest- — which show espe- 

 cially the activity of the Torreone, Sciarra, and, less often, the Zolfo vents 

 during recent years. 



In order to obtain a comprehensive survey of the occurrences of the 

 different vents shown in the preceding figures, they are summarized in 

 Table I. In this the deplorable confusion in designating the several 

 vents by letters and numbers is very evident. It was to avoid this that 

 names have been given in this paper to the vents. 



A fact brought out by the table, plans, and sketches, and one which is 

 still more emphasized when supplemented, by the verbal descriptions, is 

 the great variation in the number of vents active at different dates. At 

 times as many as seven or even eight are reported, while at others the 

 number may sink to two or even but one, while in 1897 none of the vents 

 was explosively active. It is this feature which has led many writers to 

 consider the vents of Stromboli very variable and to overlook the per- 

 sistence in location of some of them. When very numerous vents are 

 reported, it is probable in some cases and certain in others (as with 

 Wegner in 1906) that some of the so-called vents are in reality small 

 fumaroles. 



From the above survey and an inspection of the table (supplemented 

 by many verbal descriptions) it wdll be fairly evident that foci of activity 

 have existed since 1768 continuously, or almost so, at or near the site of 

 the Zolfo and Torreone vents of 1914, and rather more intermittently at 

 or near the site of the Sciarra vent. In view of the nature of the evidence 

 and the absence of any accurate surveys, it can not be asserted that these 

 foci have always occupied exactly the same locations. But when we con- 

 sider that the positions of two of them are fixed with considerable accuracy 

 by the presence of the near-by bounding ridges, while that of the other is 

 more or less nearly half way between and slightly below the other two, 

 we can l^e fairly confident that, in the case of these three, departure from 



Sir William Hamilton: Campi Plilegraei. Naples, 1776, plate xxxvii. 



