Origin of the Grand Outline Features of the Earth. 389 
angularity of the two systems. The line of active vents in 
Mexico and that of the great chain are at right angles, as stated 
by Humboldt, and the former is parallel with Cuba. The Cana- 
nes present the same facts as the Galapagos. 
We often find parts of a chain at right angles with the rest, as 
illustrated in figure 6. In the chain of lakes from Lake Erie to 
Bear, which has the northeast course, several of the lakes them- 
selves are oblong across this course. This is the case with the 
parts of Bear lake, with Slave lake, Athabasca, and the northwest 
shore of Superior; and the whole line is at right angles with the 
line of the St. Lawrence, Ontario, and Erie. Indeed such facts 
are closely connected with those first stated with regard to the 
allelism.t De la Beche mentions the same in Devon and some 
other parts of England, where north-northwest and a transverse 
direction are the common courses.{ Phillips observes that in 
Yorkshire, fifty-five out of eighty-nine of the cleavage joints ob- 
served by him, were between northwest and north, and twenty- 
eight were at right angles with these ; only six were ous. 
The same facts have been remarked by other English geologists. 
Fitton has presented similar facts from Australia.¢ Mr. Darwin 
in his work on South America, gives various facts showing that 
the principle holds west. of the Andes, that the cleavage joints 
are in general parallel to the mountain range. It is also true of 
the United States, east of the Appalachians. We observe there- 
fore that the question with regard to the cause of this structure 
1S Intimately connected with that of the origin of mountains. 
- This survey of the geological features of our globe leads to 
Several important conclusions. ies 
A. That the earth has a strongly marked physiognomy, or a 
sysiem in its grand outlines. a aut : 
B. That throughout this system, northwest and northeast lines 
are every where prevalent. ) Hie pie . 
C. That these strongly drawn lines are usually curved in- 
stead of. conforming to the direction of @ great circle; and 
Mebihai nage a: ic, ke aces adage 
~-™ Bibliothéque Uniy., de.Genéve, xliii, 166. 1930. 
t Trans, Geol. Soc., London, ii ser., iii, 68. 
t Geol. Rep. on Cornwall, Devon, and W. Somerset, 8vo, London, 1839. 
§ Sketch of the Geology of Australia, Phil. Mag., Ixviii, 135. 
