442 J U LI EN 



and materials, to subsequent erosion during base-levelling and 

 to direct attack of crossing streams. The latter characteristic — 

 topographic modification throu'gh the presence of intermixed 

 eruptives or of hard and soft derivative schists — has afforded 

 conditions most favorable for the establishment of a large city. 

 In the beginning, convenient access to both river and sea, with 

 abundance of sea-food, has been as attractive to the aborigines 

 who first chose, occupied and named these sites, as to the 

 civilized settlers who followed. Then the excellence of a deep 

 soil, rich in lime and alkalies, derived from' decay of the oc- 

 cluded lavas and traps and from their glacial attrition, has 

 offered an important condition to the agriculture of the primitive 

 inhabitants and afterward of the earlier immigrant. But the 

 main advantages for permanent human settlement have been 

 gained through the deep erosive dissection of a rock stratum of 

 varied constitution. A glimpse from a high point, near almost 

 any of these cities, reveals the essential attractions in depth of 

 water along bold shores, capacious harbor, convenience and 

 varied beauty of building sites, and access to outcrops of build- 

 ing stone, clay and sand, which have resulted directly from the 

 diversified topography but initially from its volcanic foundations. 



