426 PACIFIC OCEAN. 
north through northeast to east; and even greater variations of direc- 
tion take place in a single range. 
The truth forces itself upon the mind, in view of these facts, that 
some universal cause has operated in producing results so general, 
and so mutually dependent—a cause, through which, the very frame- 
work of the globe has received its characteristic features. We are also 
led to believe that it was in the early stages of the earth’s history that 
the grand outlines of its structure were drawn which have been since 
filled up by subsequent operations. The prevailing uniformity of 
trend in the courses of ruptures of the earth’s crust, must have pro- 
ceeded either from the nature of the crust fractured, or the direction 
of the fracturing forces, and facts show that both causes have acted. 
For the occurrence of a linear series of rents, made up of a number of 
parallel ruptures oblique to the general line, proves that there was a 
fixed direction to the power causing rupture indicated by the direc- 
tion of the line, and also a determinate structure indicated by the 
direction of the several rents. 
The existence of such a structure in the earth’s crust has been 
urged by Necker, Boase, De la Beche, Boué, Hopkins and others.* 
It has been attributed to the influence of magnetic or electrical cur- 
rents on the process of crystallization while the earth’s exterior was 
cooling from a state of igneous fusion, and also to the mechanical 
effect of an elevating force.t 
The view that the earth has cooled from a state of fusion is gene- 
rally admitted, and finds additional proof in the evidences, coextensive 
with the world, of a prevailing structure.t The influence of electri- 
* M. Nrcxer, Bibliotheque Universelle de Genéve, xlii, 180, 1833.—De ta Becne, 
Geological Report on Cornwall, Devon, and W. Somerset, p. 281, 8vo. London, 1839.— 
H. 8S. Boas, Treatise on Primary Geology, 8vo, London, 1834, and L. and E. Phil. 
Mag. and Journ. of Sci. ix. 4, x. 14.—M. Bour, Bull. Soc, Geol. de France, ii. ser. i. 355. 
t W. Horxtns, Esq., Trans. Camb. Phil. Soc. vii. 1.—C. Darwin, on South America, 
8vo. London, 1846, p. 163.—Rev. A. Sepewick, on the Structure of Large Mineral 
Masses, ‘Trans. Geol. Soc. London, ii. ser. iii, 480, March, 1835. Mr. Hopkins attributes 
the existence of parallel fissures in a region which has experienced elevation, and also of 
transverse lines, to the tension consequent on the elevation, and he shows by mathematical 
calculation that these are both necessary results of such a cause. Mr. Darwin, observing 
in western South America the general parallelism of cleavage lines to the Andes, suggests 
that the tension attending elevation, being unequal in different parallel lines, was the 
cause in this and other cases. 
t W. Hopkins, Esq., has deduced from calculations based on the amount of precession 
