66 J. W. Judd — On Volcanos. 



glass were allowed to pour forth its contents in a stream extending 

 to a length of some miles, and to a thickness of hundreds of feet, 

 what would be the nature of the phenomena attending its outburst, 

 and of the products which would result from its gradual solidification? 



This is no idle problem ; for the solution of it may be found by 

 the geologist at Campo Bianco and Rocche Eosse. 



Campo Bianco or Monte Pelato is a volcanic mountain (see Fig. 8), 

 composed entirely of the whitest fragmentary pumice, the highest 

 portion of the crater-ring of which rises to the height of more than 

 1500 feet above the sea-level. This is partially embraced (as is 

 Vesuvius by Somma) by the relics of an older and far larger cone 

 of the same materials, which culminates in Monte Chirien, having 

 an elevation of nearly 2000 feet. The soft white pumice tuffs of 

 the flanks of both these cones have suffered greatly from denuding 

 forces, acting on their light and incoherent materials, and giving 

 rise to those long furrows producing the "umbrella form" which 

 is admirably exemplified in them. The crater of Campo Bianco 

 presents at its bottom a flat plain, covered with comminuted 

 pumice-tuffs, and now forming a most productive vineyard at a 

 level of 892 feet above the sea ; its walls rising almost vertically 

 around it to heights of from 400 to 600 feet on the northern, 

 western, and southern sides. On the north-eastern margin of this 

 crater, however, a petrified cascade of vitreous lava rises 100 

 feet above the crater-floor, and, sweeping away all that side of 

 crater-wall, has poured with a current, half a mile in breadth, down 

 to the sea. This lava-stream, now covered with a reddish-brown 

 coating from the oxidation of its iron, is the Bocche Rosse. Near the 

 point where it issues from the crater, a deep "bocca" exists, once 

 evidently the place of discharge of powerful steam-jets — now an 

 awful pitfall, which the islanders avoid and speak of with terror. 

 The surface of the lava presents a most striking example of those 

 rugged cooled surfaces, like the Cheires of the Auvergne, and pre- 

 sents one of the wildest and most desolate scenes which it is possible 

 to imagine. The traversing of it is in many places a very difficult 

 task. 



Other similar cones, craters, and lava-streams abound in Lipari. 

 On the western side of Monte Chirien, at an elevation of more than 

 1700 feet, is a second crater, much ruined, that of the Piano dell' 

 altra Pecora ; and on the south side of Campo Bianco is another, 

 that of Forgia Vecchia, or Monte Perrara, at an elevation of 968 

 feet, from which another stream of vitreous lava flows to the sea. 

 At the head of this lava-stream no less than three mouths com- 

 municating with abysses of unknown depth, similar to that of the 

 Bocche Bosse, are seen. They doubtless mark the sites of explosive 

 discharges of steam. At Canneto is an older stream of perlite, which 

 probably flowed before the present crater of Campo Bianco was 

 formed. 



The craters of the southern part of the island of Lipari give rise 

 to lavas similar in composition to those of the north end of the 

 island. In the former, however, the stony characters predominate 



