338 J. D. Dana on the Plan of Development 
volcanoes are not on the east or landward side of the crest, for 
there is not a volcano on that side, but on the seaward side, and 
not very far from the ocean. Thus we may almost say, The 
nearer the water, the hotter the fire. ; 
5, Again, the mountains that make the borders, consist as is 
ments are most numerous towards the ocean, and are parallel 
nearly to the ocean. Hence again, The nearer the water, the vaster 
the plications of the rocks. 
6. Over the interior of North America, there are not only no 
volcanoes, but there never have been any since the earlier Silu- 
rian, as shown by the absence of their remains among the strata; 
and this is so, notwithstanding the abundance of salt water over 
the regions in those ancient times. Over the interior of Asia 
there are no volcanoes, as is well known, except the three or four 
in the Thian-Chan Mountains. The great volcanic belt of the 
Orient stands out a short distance from the water-line of Asia, 
in the Japan range of islands, thus directly edging the oceanic 
basin; for the intervening region of shallow waters 1s properly 
a submerged part of the continent. 
7. In contrast with this non-volcanic character of the interior 
ayas, 
28,000 feet high, is itic; and surely we might have ed 
for some granitic eas gi the central islands of the oceans: 
but there are none. 
t the same time, as others have remarked, the transverse 
seas which divide the Northern and Southern continents, the East 
Indies, the Mediteranean-and West Indies, are characterized by 
volcanoes. 
If then, the typical form of a continent is a trough or basin, 
the oceanic borders being raised into mountains; if these borders 
are so turned as to face the widest range of ocean; if the height 
of these border mountains and the extent of igneous action along 
them is directly proportioned to the size of the oceans,—the Pa- 
cific, accordingly, being girt with great volcanoes and lofty moun 
ns, while the narrow Atlantic is bounded by smaller heights 
and but few voleanoes; if, moreover, volcanoes characterize the 
islands o ‘mid-ocean and not the interior of the continents: What 
is the legitimate inference? 
Most plainly, that the extent and positions of the oceanic de- 
pressions haye some way determined, in a great degree, the fear 
