WHITE ROCKS AT PISAGUA. 125 



it is not easy to understand how the uniformity in the 

 western front could have been brought about during 

 the period of subsequent and comparatively recent 

 elevation. If this had occurred along an axis of 

 elevation near to the present coast-li-ne, the effect 

 must have been to produce a coast-range parallel to 

 that of the Andes, with a watershed having an eastern 

 as well as a western slope, and accompanying dis- 

 turbance of the strata, such as we find on a great 

 scale in western North America. Some indications 

 of such action may be seen in Chili, south of Copiapo, 

 and further to the south, but I am not aware of any 

 fact to justify a similar supposition respecting this 

 part of the coast of South America. 



On the morning of May 3 we were anchored in 

 front of Pisagua, which, being the port of Tarapaca, 

 the chief centre of the nitrate deposits, is at present 

 an active place. The houses are rather more scattered 

 than usual, some of them being built on rising ground, 

 apparently above the reach of earthquake waves. 

 The range of apparent hills, fully fifteen hundred feet 

 in height, rises steeply behind the little town, and the 

 monotonous slope is broken by a long zigzag line 

 marking the railway to Tarapaca. Some steep rocks 

 rising from the sea to the south of the anchorage 

 were in great part brilliantly white, recalling the 

 appearance of quartz veins, or beds of crystalline 

 limestone, dipping at a high angle. Thinking the 

 existence of such rocks on this coast very improbable, 

 I was anxious to inspect them ; but when I was told 

 that the time of our stay would merely allow of a 

 short visit to the town, I did not care to land. The 



