TOPOGRAPHICAL FEATURES. 425 
ternal, the general arrangement of the islands in groups and ranges, 
and the evidences of change of level in different epochs. We may 
take a more comprehensive view of the facts, and inquire still farther 
into the origin of the great system of arrangement in the Pacific 
lands, and the connexion between the prime cause of this arrange- 
ment and the extent and position of the regions of subsidence which 
have been pointed out. 
The several facts upon which our conclusions are based, may here 
be repeated :— 
1. A general linear arrangement of the groups, and their subordi- 
nation to ranges or chains, sometimes several thousand miles long. 
2. A prevalence of northwest ranges (northwest by west, the ave- 
rage course) throughout the ocean, and consequently an approximate 
parallelism of the groups from New Holland across the Pacific to 
California. Also the existence of ranges nearly at right angles with 
the prevailing northwest system. 
3. The linear groups based on a serves of ruptures, instead of a single 
uninterrupted fissure, and forming “continued,” “advancing” or 
“receding” series; with frequent parallel ruptures in the same group, 
and occasional transverse lines. 
4. A series of ruptures often largest at one of its extremities ; and 
also, the several ruptures frequently largest at the corresponding ex- 
tremity of each. 
5. A frequent curved form to long ranges, and also to subordinate 
parts of ranges: the curves either proceeding from the position of the 
parts in “advancing” or “ receding” series, or from a change of trend 
in the parts themselves, or from both these causes united. 
6. When a curving range is met by transverse ranges, the latter 
vary in direction with the curve, so that the two are nearly at right 
angles with one another. 
7. A parallelism of the groups of the Atlantic with those of the 
Pacific; and also a general parallelism between the two Pacific sys- 
tems of trends, and the direction of coast lines and mountain ranges 
throughout the globe. 
8. A tendency to curved directions in ranges and parts of ranges 
often modifies widely the courses of the earth’s physiognomic lines, 
although a prevailing northeasterly and northwesterly direction may 
be distinguished. 'The southwest lines may bend north on one side, 
and west on the other; and so the northeast may curve around from 
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