J. W. Judd — On Volcanos. 59 



The island of Lipari must be looked upon as only accidentally 

 separated from that of Vulcano and Yulcanello ; the same line of 

 volcanic cones and craters which we have described in the latter 

 being clearly continued in the former. In the southern part of the 

 island of Lipari we find at Punta Capparo, Formiche, Monte della 

 Gruardia, and Fossa del Monte, weathered and unmistakable craters 

 and lava-streams, composed of materials of highly acid or siliceous 

 character, namely, pumice and quartz-trachyte (Liparite), passing 

 into obsidian, perlite, retinite, etc., and evidently belonging to the 

 latest period of volcanic eruption. The central parts of the island 

 of Lipari are entirely composed of the tuffs and lavas of the 

 second period ; these are, however, as we have already seen, much 

 altered by the gaseous emanations, still represented by the hot 

 mineral springs of San Calogero and the stufe of Bagno Secco, 

 which must be assigned to the third period. The great central 

 crater of Monte Sant' Angelo (see Fig. 3, page 14) is thrown up on 

 the same great line of fissure which we have been tracing to the 

 southwards ; but on the west and east sides of it respectively we 

 find the smaller lateral craters of MazzaCarusee and Monte Perrara or 

 Forgia Vecchia, the latter belonging to the latest period of eruption. 



The northern part of the island of Lipari, like its southern ex- 

 tremity, exhibits a fine series of pumice cinder-cones and lava- 

 streams of volcanic glass graduating into Liparite, evidently of 

 recent origin, and forming a continuation of the same north and 

 south line of vents. These we shall presently describe in greater 

 detaiL 



Thus we have clear evidence that along a line, directed towards 

 the earliest and great central volcano of the Lipari group, at least 

 twenty distinct vents, giving rise to volcanic cones and craters of 

 varying size, have been formed. It seems probable, as suggested by 

 Hoffmann, that the volcanic products of Capo di Milazzo may bo 

 regarded as a continuation of the same line. 



The twin volcanos of Salina (the Diclyma of the ancients) with 

 those of Filicudi and Alicudi are evidently situated on another line, 

 which may perhaps be produced to Ustica. This line also radiates 

 from the same central volcanic mountain. 



Lastly, in Stromboli, with its linear arrangement of old and recent 

 craters, and in Stromboluzzo, doubtless the last relic of another 

 volcanic pile, we see evidence of a third string of volcanic vents, 

 the direction of whieh points to the same great centre of igneous 

 activity. 



That the linear arrangement of volcanos, such as we have described 

 as so well exemplified in the Lipari Islands, points clearly to the ex- 

 istence of great fissures in the earth's crust, along different parts of 

 which eruptions have successively taken place, has been recognized 

 by all geologists. Indeed, in the fissures produced at Etna during 

 the recent eruption (1874), as described by Professor Silvestri, of 

 Catania, in the earlier eruptions of the same mountain in 1669, 1811, 

 and 1819, and in many analogous cases, we have had ocular demon- 

 stration that such is the case. Fresh proofs of the correctness of 



