48 REPORT OF THE SECRETARY. 



year. In addition several thousand pamphlets and scientific periodicals have been 

 received. 



Illustrations. — The preparation of the illustrations, including the photographic 

 work, was continued under the direction of Mr. Wells M. Sawyer until March 17, 

 1898, when he resigned to accept another Federal appointment. From that time 

 until the close of the year the preparation of illustrations was conducted under the 

 able supervision of Mr. De Lancey Gill, of the United States Geological Survey, 

 through the courtesy of Hon. Charles D. Walcott, director of that Bureau. During 

 the year about 75 negatives and 610 photographic prints were made for purposes of 

 illustration and exchange. The preservation and cataloguing of the Bureau's 

 negatives have continued with the aid of Mr. Henry Walther. 



Respectfully submitted. J. W. Powell, 



Director. 



Mr. S. P. Langley, 



Secretary of the Smithsonian Institution. 



