422 PACIFIC OCEAN: 
intensity by Major Edward Sabine, R. A., in the Report of the British 
Association for 1837.* A correspondence throughout, or even in the 
majority of cases, could not properly be expected, considering the 
changes that must have taken place during the progress of the earth’s 
history, and also those other sources of influence bearing upon the 
direction of ranges of fissures. 
With regard to the action of the rupturing force, (which in con- 
nexion with a specific structure has produced the features under 
consideration,) we observe in the first place that the great length of 
ranges or chains, and the relations of long systems of curves like 
those of Eastern Asia, and also the dependence of transverse lines as 
in the East Indies and Pacific, all show that this power has exerted 
its influence on a grand scale: for these are not the effects of accidental 
earthquakes or limited agencies, but a systematic result of a general 
cause. ‘This cause we have elsewhere shown is to be found in the 
contraction that attends cooling. The reality of this force cannot be 
doubted ; and the only question with us is whether the effects in view 
correspond or not with those that would proceed from this cause. As 
this subject is presented by the writer in another place,} we offer here 
only a brief statement of it. 
After a cooling globe is incrusted over by refrigeration, the contrac- 
tion still going on beneath as the cooling progresses places the crust 
in a state of tension; the contraction tends to draw it towards the 
centre, which effect its own rigidity resists. It is this power of tension 
ina Princé Rupert’s drop (a drop of unannealed glass) that causes it 
to fly into a thousand fragments when the surface is merely scratched 
and the balance of forces disturbed: and the same principle operates 
on a scale of immensely greater magnitude in a globe of cooling rock. 
This tension, therefore, must necessarily produce fractures and dis- 
placements. 
The direction of this force will depend on the rate of cooling in dif- 
ferent parts, and also on that change in the earth’s oblateness that 
would accompany a diminution of the earth’s diameter. Large 
portions of the globe might cool before others, and this would modify 
the amount of force in different parts, as well as the mode or direction 
of its action. 
Now we ascertain from the continents that they were early free 
* Report of the Seventh Meeting of the British Association for the Advancement of 
Science, held at Liverpool in September, 1837, vol. vi. London, 1838. 
t+ American Journal of Science and Arts, i. Ser. 1. 335, and ill. 94, 176, 381. 
