Page:Popular Science Monthly Volume 69.djvu/493

Rh

from any number of little craters scattered all over it. Around these craters, the rocks were all crusted with yellow sulphur.

In a later letter, written from Yokohama, Dr. Gilbert said:

I wrote you a full account of Bogoslof, but the letter seems to have miscarried. Our discovery seems to have been corroborated later by some revenue cutter, but if the newspaper report agrees with their findings, very extensive changes took place in the interval between the two visits. When seen by us, the new cone, occupying much of the space between the two older ones, was somewhat higher than either, but was certainly far from 900 feet high—300 feet would be an extreme figure. There was no evidence of a central crater. The steam and fumes were given off most abundantly from cracks and fumaroles on the slopes. About these were heavy incrustations of sulphur. We saw no indications of boiling water, nor did we believe that landing would be impossible.

In an account of the physical history of the Bogoslofs, written in 1899 for the report of the Harriman Expedition, Dr. Grove K. Gilbert, of the U. S. Geological Survey, noting the rapid disintegration of the islands, said:

One might predict that in the next century the name Bogoslof would attach only to a reef or shoal, were it not for the possibility of new eruptions. The pulse of the volcano is so slow that we have noted only two beats in more than a century, but such sluggishness must not be taken as a symptom of death, or even decline, for volcanic organisms are characteristically spasmodic in their activity. Long before the sea has established its perfect sway the arteries of the mountain may again be opened and a new and larger island put forth to contest its supremacy.

Nearly a century elapsed between the arrival of the first and second Bogoslof, only twenty-three years between the second and third.

The floor of the depths of Bering Sea in this region seems to be still unsettled, and astonishing changes may be looked for at any time. If it should prove true that the geological faults of California extend out from this center, a new interest would be attached to the outbreaks of Bogoslof.