J. W. Judd — On Volcanos. 255 



and the sea-water being thus admitted, a most beautiful basin was 

 formed, within which ships can lie in perfect security ; this natural 

 basin now affords by far the best port in the island. (See Fig. 16.) 



The recent date of the cones, craters, and lava-streams just 

 described, is proved by their very fresh appearance. It is probable 

 that some at least of them were produced during the outbursts, 

 accompanied by such terrible earthquakes that the inhabitants 

 were compelled for a time to abandon . the island, which we 

 know from historical accounts to have frequently taken place. 

 Great eruptions are recorded as having occurred in Ischia about 

 the year 470, between the years of 400 and 352, and in that of 

 89 b.c, and between 79-81, 138-161, and 284-305 a.d. After an 

 interval of nearly a thousand years, the great outbreak of 1301 took 

 place. The attempts which have been made to identify the various 

 recorded outbursts before the long period of rest, with existing cones 

 and lava-streams, are, it seems to me, at best very conjectural ; but 

 that the eruption of 1301 gave rise to the crater known as the 

 Cremate, and the lava-stream of the Arso which flows from it, there 

 is not the smallest room for doubting. 



The Cremate is situated in a deep valley in the east side of 

 Epomeo, and constitutes a perfect example of a small volcanic 

 cone which has been breached by the outflow of a great current 

 of lava. By descending the interior slopes of the crater, we find 

 its walls to be composed of the scoriae derived from the same 

 peculiar trachyte which constitutes the Arso lava-stream. These 

 scoriae are black cinder-like masses (weathering to a reddish colour), 

 completely filled with the entangled crystals of sanidine and other 

 minerals which occur porphyritically imbedded in the solid lava. 

 Sometimes the lava blocks have a vitreous base, and resemble 

 " pitchstone-porphyry," and in these cases the scoriae derived from 

 them have a pumiceous character. Alternating with the great 

 masses of agglomerate, the blocks of which are of all sizes, some 

 being very large, are a number of subordinate lava-currents, of the 

 same petrological character as the principal lava-stream. The great 

 lava-current of the Arso has risen from the bottom of the crater of 

 the Cremate, and, sweeping away its western side, has flowed down 

 to the sea, along the line of valley between Bagno and the city of 

 Ischia, a distance of about a mile and a half. The highest point of 

 the Cremate is 763 feet above the sea, the bottom of its crater 528. 

 From this lowest point the lava has boiled up to the height of 597 

 feet, and here forms a number of ridges composed of blocks set on 

 end and scattered about in the wildest confusion. Thence following 

 the course of the valley, and widening as it approaches the sea, the 

 lava-current forms an extremely rugged Cheire, the surface of which 

 is only very scantily clothed with broom, while numerous trees of 

 the well-known Italian stone-pine have sprung up here and there in 

 its hollows. At a number of points nests of specular iron and other 

 products of sublimation from the cooling lava are found, and one 

 vent still exists from which hot vapour continues to issue. 



The accounts of the great eruption of 1381 which have come 



