One of the grandest facts which the science of geology has established up to the present time is the existence of a great world-belt, or girdle, of Tertiary fold-mountains almost encircling the earth. This mountain belt comprises the entire Pacific coast of the two Americas and of Asia and extends westward along the southern border of Asia and Europe to the Atlantic coast in Spain and Morocco. In the Malay archipelago the belt branches to the eastward and sends an arm around the northern and eastern sides of Australia, but the mountain ranges of this branch are mostly submerged, and are now represented only by island chains, including New Guinea, New Caledonia, New Zealand, and many smaller islands. Excepting the gap between New Zealand and southern Chile, the Pacific Ocean is completely surrounded by the Tertiary mountain belt. This fact rests upon a sound basis of observations, and is . . .