J. W. Jucld — On Volcanos. 147 



thus briefly noticed the salient features presented By Stroruboli, 

 the reader will have less difficulty in following the descriptions 

 of the state of the volcano at different periods as borne witness to 

 by various observers. 



About the year 1744, according to an account received by Spallan- 

 zani, the volcano threw out such an enormous quantity of scoria? as 

 to cause a " dry place in the sea," which remained for some months 

 as a hill rising above the waters, and then gradually disappeared. 

 The probable interpretation of this is that, during a more than 

 usually violent paroxysm of the volcano, a lateral cone was formed 

 on the submerged flanks of the mountain, and, rising above the sea- 

 level, was gradually destroyed by the action of the waves, in the 

 same manner as in the well-known case of Graham's Isle. 



In 1768, that able observer of volcanic phenomena, Sir William 

 Hamilton, returning from a visit to Etna, was becalmed for three 

 days among the Lipari Islands. Hamilton, at this time, not only 

 saw the usual explosions of red-hot stones, but noticed that " some 

 small streams of lava issued from its side, and flowed into the sea." 

 A drawing by Signor Fabris, who accompanied Sir William Hamil- 

 ton on this occasion, shows that, not only was the crater at this time 

 in a state of rather violent activity, but that two lateral outbursts 

 were taking place low down on the south-western flank of the 

 mountain, not far from the hamlet of Ginostra. A copy of this 

 drawing of Stromboli, made in 1768, is given in Plate VIII. 



In 1770, according to Biydone, the volcano was more than usually 

 active, and a submarine eruption took place near it. This author 

 correctly describes the crater as situated at 200 yards below the 

 summit of the mountain, but declares that while its action sometimes 

 resembled that of Vesuvius (then in a state of moderate activity), 

 " the explosions of which succeed one another with some- degree of 

 regularity, and have no great variety of duration," yet, at times, " a 

 clear flame issues from the crater of the mountain, and continues to 

 blaze, without interruption, for near the space of half an hour." Bry- 

 done had never seen a similar illumination of Vesuvius, except when 

 the lava had risen to the summit of the mountain. In the descrip- 

 tions of Brydone, then, we have evidence that in Stromboli and 

 Vesuvius the usual features of their action were temporarily reversed : 

 the former was passing through a violent paroxysm, while the latter 

 exhibited a succession of subdued and almost rhythmical explosions. 

 This is a most significant circumstance, and one which affords a 

 complete refutation of the view that a fundamental difference exists 

 between the nature, modes of action, and causes of the phenomena 

 presented by these two volcanos. 



Between the years 1766 and 1781, Dolomieu was twice in the 

 vicinity of Stromboli during a time of sudden storm. He then saw 

 the volcano making rapid explosions at intervals of two or three 

 minutes, and throwing out stones, which fell into the sea at a dis- 

 tance of more than 200 feet, while the glow of light above the crater 

 was very brilliant, and continued incessantly. 



Veiy striking, however, were the differences in the state of the 

 volcano which were noticed by the same distinguished observer when s 



