ACTIVE VOLCANOES OF THE SOUTH SEAS 603 
TWO ACTIVE VOLCANOES OF THE SOUTH SEAS 
By Prorrssor HENRY E. CRAMPTON 
BARNARD COLLUGE, COLUMBIA UNIVERSITY, AND THE AMERICAN MUSEUM OF 
NATURAL HISTORY 
N the course of a fourth journey among the islands of the Pacific 
Ocean, during the year 1909, the rare opportunity was presented 
of making an ascent of the remarkably active volcano formed about 
five years ago on the island of Savaii, the largest member of the Samoan 
group. In addition, during a short stay in the Hawaiian Islands, a 
visit was made to Kilauea, a voleano which in contrast with the former, 
has a long geological history, for records of its intermittent periods of 
activity cover more than a century. It is the purpose of the present 
articlé to give a short general description of these two volcanoes. 
Under any circumstances such works of nature would arouse the 
interest of a student of natural phenomena; but in my own case the 
opportunity to study them was valuable for additional reasons. My 
investigations of the distribution and evolution of the land snails of 
Polynesia demanded a thorough exploration of volcanic islands of 
ereater age, islands that for many centuries have been sculptured by 
the elements so as to display alternating ridges and valleys radiating 
from their high central peaks. Tahiti is perhaps the most beautiful 
example of such an island. One finds that the several islands of the 
Pacific groups are of various geological ages, and consequently ex- 
hibit different degrees of weathering. They thus constitute a series 
showing how ancient rugged islands like Tahiti and Moorea have been 
derived from newly formed volcanic mountains like those of the 
Hawauan and other groups, which possess relatively even sides of lava 
fields unfurrowed by erosion. Furthermore the various islands scat- 
tered throughout the vast areas of the Pacific Ocean are interesting to 
the naturalist because of the evidences they give of great changes in the 
level of the ocean bed, and also on account of the réle played by corals 
in the construction of many types of islands. With few exceptions the 
islands occur in groups or chains suggesting the conclusion that they 
are the peaks of a range of mountains formerly connected by lowlands 
but now separated as the result of a subsidence of the ocean’s floor. 
Every one is familiar with the theory that a coral atoll, consisting of a 
living reef bearing a more or less extensive series of coral islets, is 
built upon such a voleanic peak, which, according to Darwin and 
Dana, has been withdrawn below the water’s level and overgrown by 
coral as it slowly subsided. It may be, as Agassiz contends, that a coral 
