sheet of rubber and draw it out in one direction, we obtain a similar picture. One diameter increases, the other diminishes. By the stretching of the rubber, all groups of points (groups of islands) are drawn into chains parallel to the length, and rifts are torn open perpendicular to the direction of tension. The island festoons of East Asia are thus in close relation to the structure of the whole Pacific Ocean.
Absolutely similar festoons are present in the West Indies; and the arc of the South Antilles between Tierra del Fuego and Graham Land can also be claimed as consisting of a free festoon, although with a somewhat different significance.
The uniform arrangement of the festoons in echelon is very striking. The Aleutian Islands form a chain which farther east in Alaska is no longer a coastal range, but comes out from the interior. They end near Kamtschatka, and thenceforward the Kamtschatka chain, hitherto an interior range, and the Kuriles, form, as the outermost chain, the festoon. This ends in turn near Japan to give place to the Sakhalin-Japan chain, which up to that point is an inland range. This arrangement can be still further followed south of Japan until the relations become confused near the Sunda Islands. The Antilles also show exactly the same arrangement. It is obvious that this echeloned formation of the festoons is a direct consequence of the arrangement in echelon of the former coastal mountain chains of the continents, and thus goes back to the general law of the echeloned succession of folds described above. The strikingly similar length of the arcs (Aleutian 2900, Kamtschatka-Kuriles 2600, Sakhalin-Japan 3000, Korea-Riu-Kiu 2500, Formosa-Borneo 2500, New Guinea-New Zealand formerly 2700 km.)[1] could perhaps have been pre-
- ↑ The West Indian arcs show, however, a gradation: Lesser
