1878.] 349 [Rathbun. 



succeeded by Mr. Luther Wagoner, who resigned in July, 1877. 

 Mr. Frank Carpenter then became the engineer of the Survey, and 

 continued in this capacity to the time of the death of Prof. Hartt. 

 Mr. Derby and myself arrived in Brazil only at the close of 1875. 

 No other changes than the above occurred in the personnel of the 

 Commission, and the difficulties constantly attending the exploration 

 of such a large country, with so small a staff, can be readily imag- 

 ined. 1 



When the National Museum of Rio de Janeiro was entirely 

 remodeled, in 1876, the Minister of Agriculture, having the matter 

 in charge, solicited Prof. Hartt's assistance, and, at the same time, 

 made him director of the department of Geology; but his many 

 other duties soon forced him to relinquish the new task. 



Prof. Hartt's plan of operations was to first make a preliminary 

 reconnaissance of all the accessible portions of the Empire, before en- 

 tering much into detail work ; but, as will be seen in the sequel, he 

 succeeded in very thoroughly investigating some of the regions he 

 explored. The following general account of the explorations of the 

 Brazilian Survey is based in part upon some of Prof. Hartt's unpub- 

 lished general reports. Regarding the character of the work Prof. 

 Hartt states in one of his late reports to the Minister: " As is 

 the duty of every scientific man, I have carried on my investigations 

 in a purely scientific way, hoping that later on they would not fail to 

 be of practical importance." While awaiting instructions, Hartt vis- 

 ited the gold regions of Sao Gohcalo and Campanlia. An account of 

 the results of this trip was published in the American Journal of 

 Science and Arts for June, 1876. 



The active work of the Commission began in June, 1875. They 

 explored the Cretaceous deposits near the coast, from Pernambuco to 

 Parahyba do Norte, taking Maria Farinha, where Cretaceous fossils 

 were found in 1870, as a basis. This formation was found to be very 

 extensive and richly fossiliferous. With the marine fossils of Maria 

 Farinha were discovered the remains of a large species of crocodile; 



1 It is most fitting to mention here the name of Major O. C. James, of Rio de 

 Janeiro, the oldest and most valued friend of Prof. Hartt in Brazil. From the first 

 day Prof. Hartt arrived in that country to the time of his death, he was con- 

 stantly indebted to Major James for assistance and advice, and to him, in large 

 part, was due the successful organization of the Geological Commission, for which 

 he acted in the capacity of Secretary, his services being rendered gratuitously. 

 His long experience in Brazil made him an invaluable auxiliary to the Commis- 

 sion, and he labored for it indefatigably. 



