STROMBOLI 265 



the crater. In spite of its peculiarities,"^ which led Bergeat^^ to remark, 

 ^'Seine abentenrliche Zeichnnng, ans der man sich nnmoglich orientieren 

 kann," one can readily make out the foundation of fact underlying its 

 Brocken-like character and see that the general features and the positions 

 of the main vents correspond in a general way with those which we have 

 noted in preceding descriptions. ITnreally jagged as they are, we see the 

 boundaries of the crater terrace, with the southern scarp and the two 

 lateral ridges. The Zolfo and Torreone vents are here, with the Sciarra 

 vent (number 3) between them, at the beginning of the Sciarra, while 

 behind, amid the clouds of vapor, is a representation of what may be 

 supposed to be the Central vents. 



iilthough not germane to the subject, it is interesting to note the pres- 

 ence of a smoke ring rising from the Torreone vent (number 2 of plate) — 

 the first representation of a phenomenon afterward photographed and 

 described by Perret.^^ It may be remarked that Palsterkamp (volume II, 

 page 343) attributes the rings to phosphuretted hydrogen. 



Figure 17 is a reproduction of Spallanzani^s quaint engraving^^ of 

 Stromboli in October, 1788. Here, with the aid of his graphic description 

 and a little imagination, we can recognize our old friend, the Zolfo vent, 

 though in somewhat fanciful disguise, while on the west (east in the 

 text) a column of smoke rises from the Torreone vent. These would 

 seem to have been the only vents active at this time. The line of fuma- 

 roles along the Filo del Zolfo is clearly shown. 



The next illustration, plate 8, is HoueFs^^ artistic colored lithograph 

 of the crater in 1776, taken from the west. In this the Sciarra vent is 

 in full activity, the Zolfo vent also active beyond it, and the Torreone 

 vent less so. There is much "smoke'^ above the crater terrace, indicating 

 the presence of some active vents there. Houers plate LXXI, of the 

 Sciarra from the sea, also shows the Sciarra vent. 



Comparing this with Bomemann's sketch (figure 15), both taken from 

 about the same spot, it is interesting to note (again as confirmatory of 

 the general correctness of both) that the outlines of the Torreone in each 

 are essentially alike, even to details, and that the somewhat sharp shoulder 

 below the end of the Filo del Zolfo in figure 15 is clearly seen in plate 8. 

 These points of identity are especially noteworthy, as the one was made 

 eighty years later than the other. 



2" There is a discrepancy between the text and the plate as regards the numbering of 

 the vents 1, 2 and 6, 5 ; probably an engraver's error. It does not affect the argument. 



28Bergeat: Op. cit, p. 32. 



29 F. A. Perret : Amer. Jour. Sci., vol. xxxiv, 1912, p. 405. 



^ L. Spallanzani : Viaggi alle due Sicilie. Milan, 1825, vol. ii, plate iii ; cf. pp. 267- 

 270. 



^ J. Houel : Voyage Pittoresque des lies de Sieile, etc., Paris, 1782, pi. Ixxii. 



