K78.] 361 [Hart 



" Mr. Carpenter has been engaged in the reduction of the geograph- 

 ical observations of the various members of the Commission, in the 

 preparation of a new map of the Lower Amazonas, in the revision of 

 a paper on meteorology presented by Mr. Wagoner, and recently in 

 the preparation of a carefully considered expose of the methods em- 

 ployed by the United States Government in geographical surveying 

 in the western territories and states, — methods sufficiently accurate, 

 and especially adapted for a new and unexplored country, and* most 

 admirably adapted for a geological survey, where geographical and 

 topographical work must to a certain extent be subordinated to the 

 needs of geological exploration. Mr. Carpenter, after a severe train- 

 ing as a civil engineer, was employed by Lieut. Wheeler on his sur- 

 vey, under the War Department, of the western territories, and has 

 had several years of practical experience in the field. I have thought 

 that, even if the Geological Commission of Brazil should be defi- 

 nitely stopped, his paper would be one of the most valuable contribu- 

 tions that the Commission could make to Brazilian geographical and 

 geological science. A few years ago Mr. Carpenter published in the 

 United States a very short article on the same subject, which for its 

 novelty and its clearness attracted very general attention. The me- 

 moir written for the Commission is a very much more extensive and 

 valuable document, presenting for the first time clearly the methods 

 chosen after long experience by the United States Government for 

 the exploration of a region almost identical with Brazil in its leading 

 features, and which has been sanctioned by the most eminent of 

 explorers. 



" Dr. Freitas, though suffering from the effects of his journey on 

 the Amazonas, has continued faithfully to perform his arduous duty of 

 translating into Portuguese the paheontologieal reports of Messrs. 

 Derby and Rathbun. I cannot speak in too high praise of his fidel- 

 ity and industry. As it was simply impossible for one person to 

 translate the material rapidly accumulating from the different mem- 

 bers of the Commission, I found it necessary to call in the aid of my 

 friend, Dr. Americo dos Santos, who, during the last two months, has 

 done everything in his power to aid in the work, translating carefully 

 the memoir of Mr. Carpenter and various papers embraced in the 

 voluminous relatorios on the Lower Amazonas. 



"In accordance with the custom of other commissions and museums, 

 I have employed an experienced Italian artist as a preparador of 

 specimens, and for the making of casts and reproductions of rare fos- 



