13 



personal observations made in the vicinity ot Rio, Ba- 

 hia, etc. 



The above general account suffices to show how little 

 was known of the systematic geology of Brazil, at the 

 time when Hartt had finished his second trip to that 

 country. 



In the year 1870, the same in which his book was issued, 

 Prof, Hartt organized the largest of his own expeditions 

 from the United States. It was composed, besides him- 

 self, of Prof. Prentice and eleven students of Cornell 

 Uaiversity. His object in taking so many young men 

 into a new field was to give them thorough practical 

 training, and to stimulate them to undertake original 

 work. He says, in his report of this expedition, that he 

 did not expect to make scientists of them all, but hoped 

 that some might be thus induced to accept that calling. 

 Of that band of students he refers to four (O. A. Derby, 

 T. B. Comstock, H. H. Smith, and W. S. Barnard), who 

 are to-day doing scientific work of a high character. 

 The means for defraying the expenses of the trip were 

 contributed by several parties, most prominent of whom 

 was Mr. E. B. Morgan of Auroi'a, N. Y., whose name has 

 been given to this and the subsequent expedition. 



Not having been successful in his former trips along 

 the coast, in finding other fossiliferous deposits than the 

 Cretaceous, Prof. Hartt determined to change his field of 

 research, and explore the Amazonas. Accordingly, he 

 went with his party directly to Para, and in the neighbor- 

 hood of that city spent some time in training his inexpe- 

 rienced assistants. The tributary rivers, Tocantins, 

 Xingu, and Tapajos, were then examined throughout 

 their lower courses, and many valuable geological facts 

 ascertained. On the Tapajos were discovered the highl}^ 

 fossiliferous Carboniferous deposits from which, as already 

 mentioned, Major Coutinho had before obtained some 

 undetermined fossils. 



At the falls, on each of the above named rivers, were 

 found series of metamorphic rocks, which have been 

 referred, from their position and lithological characters. 



