30 



PHYSIOGRAPHIC GEOLOGY. 



then returning again more or less nearly to their former course, and 

 that the peaks of a ridge are very far from being in an exact line 

 even over a short course ; again, that several approximately parallel 

 courses make up a chain. 



A. Northwesterly system op trends. — In the southwestern 

 Pacific, the New Hebrides (Fig. 23) show well this linear arrangement ; 

 and even each island is elongated in the same direction with the group. 

 This direction is nearly northwest (N. 40° W.), and the length of the 

 chain is 500 miles. New Caledonia, more to the southwest, has 

 approximately the same course, — about northwest. Between New 

 Hebrides and New Caledonia lies another parallel line, the Loyalty 

 Group. The Salomon Islands, farther northwestward, are also a linear 

 group. The chain is mostly a double one, consisting of two parallel 

 ranges; and each island is linear, like the group, and with the same 

 trend. The course is northwest-by-west, the length 600 miles. 



In the North Pacific, the Hawaian range has a west-northwest 

 course. The Sandwich or Hawaian Islands (Fig. 24), from Hawaii to 





Fig. 23. 



15° S 



170° E 

 J\/1 





o 



Ox 





'XO 



Kauai, make up the southeasterly part of the range, about 400 miles 

 in length. Beyond this, the line extends to 175° E., making a total 

 length of nearly 2,000 miles, — a distance as great as from Boston to 

 the Great Salt Lake in the Rocky Mountains, or from London to 

 Alexandria. Moreover, in this chain, there are on Hawaii two sum- 



