270 H. S. WASHINGTON PERSISTENCE OF VENTS AT STROMBOLI 



Since the crater was first observed b}^ Europeans in 1823, this small lake 

 has occnpied about the same position and has been the center of activit}^ 

 This is clearl}^ shown by the series of plans and records published by 

 Dana^^ and Brigham.^* Dana (page 33) prefaces the record by saying: 

 "The most active fires in 1840 were in the southwest part of the crater^ 

 as has been the fact through all the known history of Kilauea." Similarly 

 Hitchcock^^ says: "Halemaumau is always the place where the fire may 

 be seen. It might be called the core or nucleus of the volcano/^ In the 

 eastern part of this pit is a pulsing ^'fountain/' about 20 meters in diam- 

 eter, called "Old Faithful," presumably above the narrow conduit, and of 

 which Daly^® remarks that it "has represented the true axis of the lava 

 column for many years and seems to have been the main source of mag- 

 matic heat throughout the known history of Kilauea/' 



Here, then, we have another case of the persistence in location of a 

 vent and conduit in a crater floor for a considerable known period of 

 time — nearly 100 years. It is also noteworthy that, though the lavas at 

 the two volcanoes are chemically very similar, Stromboli and Kilauea are 

 of very different types, both in volcanic form and in mode of activity. 



Etna and Vesuvius 



Although the recorded descriptions, plans, and views of the craters of 

 these two volcanoes, especially the latter, are more numerous and date 

 farther back than is the case with Stromboli or Kilauea, yet they furnish 

 us with little information regarding the question of the persistence of the 

 vents. This is due partly to difficulties of observation and, as already 

 pointed out, partly because of the approximately circular shape of the 

 craters, their greatly varying diameters, depths, shapes, and rim outlines, 

 so that there are no permanent points of reference by which to identify 

 locations. In general, the only indication that can be given is reference 

 to the compass position, and in the earlier sketches this is often rendered 

 unavailable by neglect to state the direction of the viewpoint. 



But definite cases of apparent persistence in location of vents at these 

 volcanoes are furnished by Etna. A plan of the crater in 1897 and a pho- 

 tograph of it in 1901, published by Eicco,^^ show the chief active vent in 

 the northwest sector of the crater floor close to the wall — that is, in ap- 

 proximately the position of one of the two vents present in July, 1914.^* 



Tliree sketches by M. Gemellaro, reproduced by Sartorius v. Walter- 



2" J. D. Dana: Characteristics of volcanoes, New York, 1890. pp. 45 ff. 

 3* W. T. Brigham : Mem. Bishop Mus., vol. ii, no. 4, 1909. pp. 418 f£. 

 3= C. H. Hitchcock : Hawaii and its volcanoes, Honolulu, 1911, p. 258. 

 ^OR. A. Daly: Igneous rocks. New York. 1914, p. 266. 

 37 A. Ricco : Boll. Soc. Sism. Ital., vol. vii, 1901, fig. 5 ; fig. 2. 

 . 38 Washington and Day: Bull. Geol. Soc. Am., vol. 26, 1915. p. 382, and pi. 18. 



