A visit to Stromboli1 in August, 1914, brought to my attention a feature of this volcano which has been overlooked generally by writers on volcanism. This is the apparent persistence in location of several of the active vents in the crater floor or “terrace” for a period of at least about a century and a half. Further consideration of this and other features of the Stromboli vents, as well as of similar features at other volcanoes, have led me to some generalizations in regard to the mechanism of volcanic action.
Briefly put, there are at Stromboli certainly, three, and probably six, vents which have persisted in location for a very considerable length of time. These vents are all of small diameter, contiguous to each other within a small area, and one or more of them have been more or less continuously active. As will be shown, they are presumably . . .