VOLCANOES OF THE SOUTH SEAS 177 
It is true that I was interested in these Pacific islands also for reasons 
less closely connected with my work. For instance, the various islands 
give evidences of great changes in the level of the ocean bed and also explain 
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 con- 
nected 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Dana, has been withdrawn below the water’s level and overgrown by coral 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 atoll 
is built upon a submarine volcanic mountain upheaved from the ocean’s 
floor; but in either case the relation between coral reefs and volcanic peaks 
is one that possesses a real importance for the zodlogist. 
The two volcanoes of Savai and Kilauea occur in island groups that 
are In every way typical of the so-called “high” islands of the Pacific Ocean. 
The Samoan Islands, containing Savaii, lie almost on a straight line running 
nearly east and west. Upon examination they prove to be of various ages, 
for the westernmost, Savaii, bears the voleano that is active and has other 
indications that it is more recent in origin than its neighbor, Upolu; this 
island, in its turn, is younger than the more rugged Tutuila and Manua 
to the east. The Hawaiian Islands, containing Kilauea, also range with 
some regularity along a line, which in this case runs west-northwest and 
east-southeast; but one very interesting difference consists in the fact that 
the newest island, Hawaii, lies at the eastern end of the group, while the 
relative geological ages of the other islands correspond with their serial 
geographical order westward to Kauai, the oldest and most sharply sculp- 
tured member of the group. In all other essential respects, the Samoan 
and Hawaiian Islands are closely similar. 
The new volcano on the island of Savaii is assuredly very impressive. 
Its total mass is great, but this feature is not so striking as its remarkably 
rapid development in the short period of five years; this development and 
the continual flow of fiery lava from its vast crater entitle it to supreme 
place in the array of voleanoes now in activity. It lies about eleven miles 
back from the coast nearly opposite the middle of the north shore of Savaii, 
which is roughly rhomboidal in outline and forty miles long. Approaching 
this part of the island by day, the most striking features of the panorama 
are the two vast clouds of steam that rise from the places where molten 
lava pours in cascades into the ocean. Upon the glistening black slopes 
beyond, jets of vapor mark the vents in the roofs of the tunnels through 
