SUMMARY. 295 



bottom of the western longitudinal valley is brought above water level, 

 appears in extreme northern Patagonia and the region to the northward, 

 where it embraces the principal agricultural lands of Chili. 



In bringing to a close this volume, which has grown far beyond the 

 proportions originally intended, the writer wishes especially to give recog- 

 nition to Mr. O. A. Peterson, his assistant and companion on the first and 

 third expeditions, and to Mr. A. E. Colburn, who accompanied him in 

 the same capacity on the second expedition. For whatever success may 

 have fallen to these expeditions, these gentlemen are deserving of equal 

 credit with the leader, and it affords me great pleasure to state that their 

 loyalty, perseverance and industry were, on all occasions, most exemplary. 



