396 Origin of the Grand Outline Features of the Earth. 
transverse son in an elliptical area under a state of tension, on 
nly remove any difficulty arismg from the existence of tw 
transverse systems and their rectangular intersections, but set 
ally require this result.* 
non-contraction or of comparative slow Pri = 
should modify the direction of the ranges of fissures formed in 
surrounding region where more rapid contraction is going on. 
Also, the mterference of two contracting areas would uce 
irregularities ; still wider effects would proceed from more ex- 
tended combinations, such as have produced the Scarpa eo 
sions and the continental areas. 'Thus the contine i 
were early free from firest have generally experienced aha allie 
along their borders; and fissures and mountain ranges, frequently 
several in parallel series, have been formed, whose main courses 
are a resultant between the direction of the planes of cleavage 
and the action of the force of tension arising 
a the sedtiacren going on over the oceanic areas.{ Causes 
certain irregularities in mountain ranges were mentioned on 
pot 185 of the last number of this Journal, and these discussions 
afford a more extended view of the action of these causes. The 
principles cegeormnsy in the paper just referred to, have here their 
full applica 
* positions of some — contracting areas pare eee 
~The great Pacific range 0 - lands, from the Mars hall Isl- 
eth, has been de 
scribed as convex to the Hepes while the line of the Ha- 
waiian range, 2000 miles long, is neatly straight. May not this 
part of the ocean have been one of the large compound ¢ contract 
. ing areas, and a line from Pitcairn’? as in lat. 25° S., long. 130° W., 
to northern Japan the course of its pais? Using “the registers 0 of 
ae § 
* The mathematical deductions of Mr. Hopkins were made with Lege refer- 
ence to the elevation of the Wealden, thong ought out so as to be of ge neral 
pp! ays down the facts, that in “ districts where faults oun ti 
distinct systems are usually found, in each of which the faults approximate 1 
paralleli th other; and t “the common direction x 
ays is approximately perpendicular to that of the other;’’ an establishes 
necessary dependence of these transverse systems by calculati 
mode of producing the tension required by fracture is different In the fore- 
going explanations, fi what is asst Mr. opkins; but it does not appear 
to alter the erpern results; and it is believed to set aside some objections urged wed 
e to the conclusions of Mr. Hopkins. See L. and E. oat |. Mag., and 
of i. 4, 171, 368, and x, 14. 
this Journal, ii, 132, and iii, 181. t Ibid, iii, 98, 181 
