DIRECTIONS FOR THE WEST. 423 



that I could not deliver my letters for him. I 

 saw, however, Colonel Abert, the head of the 

 topographic office, who gave me important in- 

 formation about the West for the very season 

 when I am likely to be there. I am indebted 

 to him also for a series of documents concern- 

 ing the upper Missouri and Mississippi, Cal- 

 ifornia and Oregon, printed by order of the 

 government, and for a collection of fresh- 

 water shells from those regions. I should 

 like to offer him, in return, such sheets of the 

 Federal Map as have appeared. I beg Guyot 

 to send them to me by the first occasion. 



As I was due in Boston on an appointed 

 day I was obliged to defer my visit to Rich- 

 mond, Charleston, and other places in the 

 South. I had, beside, gathered so much mate- 

 rial that I had need of a few quiet weeks to 

 consider and digest it all. Returning there- 

 fore to Philadelphia, I made there the ac- 

 quaintance of Mr. Haldeman, author of a 

 monograph on the fresh-water shells of the 

 United States. I had made an appointment 

 to meet him at Philadelphia, being unable to 

 make a detour of fifty leagues in order to 

 visit him at his own home, which is situated 

 beyond the lines of rapid transit. He is a dis- 

 tinguished naturalist, equally well versed in 



