REPORT OF THE SECRETARY. 19 



the four parts so far issued being devoted to coal products, fertilizers, 

 sulphur, and coal. 



Additions to the Museum library amounted to 3,230 volumes and 

 1,571 pamphlets, making the present aggregate of 52,534 volumes and 

 84,491 pamphlets and unbound papers. To the Biltmore collection 

 of botanical works, presented by Mrs. George W. Vanderbilt, 2,000 

 volumes were added. 



BUREAU OF AMERICAN ETHNOLOGY. 



The activities of the Bureau of American Ethnology are limited 

 to the study of the past and present conditions of the North Amer- 

 ican Indians. Their main purpose is to perfect the existing classifica- 

 tions of the various stocks of these aborigines based on their language 

 in order to discover their relationship, and to gain a clearer insight 

 into the origin, history, and migration of man on this continent. 

 The languages of the Indians are doomed to disappear in the near 

 future ; some have already gone and others will become extinct in a 

 few years. Through intense, patient research the bureau is under- 

 taking the task of recording these vanishing tongues before they dis- 

 appear forever. 



The bureau is also, through archeological work, resurrecting from 

 the night of the past hitherto unrecorded chapters of the history of 

 aboriginal Indian life that reached a high development and disap- 

 peared before recorded history began. One evidence of a prehistoric 

 phase of Indian life is indicated by the pueblos and cliff dwellers. 

 Through erosion by the elements and vandalism due to man these re- 

 markable houses are rapidly falling into decay. The Bureau of 

 Ethnology is cooperating with the Department of the Interior in the 

 excavation and repair of these remains in order that they may be of 

 educational value and preserved for posterity. 



The field researches of the bureau the past year have been particu- 

 larly important, both from ethnological and historical points of view. 

 Hitherto unknown prehistoric monuments have been discovered and 

 surveyed, while others previously known have been excavated and 

 permanently preserved. The advances made in ethnological knowl- 

 edge, although often slow, are always important and have opened up 

 new problems pleading for solution, indicating that the work of the 

 bureau has barely begun, and that much available information re- 

 garding our aborigines still remains to be gathered. 



NATIONAL ZOOLOGICAL PARK. 



Increasing popular interest in the Zoological Park is manifest by 

 the number of visitors, which aggregated 1,593,337 in 1918 as com- 

 pared with 564,634 in 1909 and 633,526 in 1913. The park is an edu- 



