Washington, D. C, July 1, 1876. 

 Sir : In obedience to your orders I have tlie lionor to present herewith 

 my report of the astronomical and barometric work done in the Black 

 Hills of Dakota and Wyoming, during the summer of 1875, while attached 

 to the party under your direction 



Very respectfully, your obedient servant, 



HORACE P. TUTTLE, 



Astronoyner. 

 Walter P. Jenney, Geologist in charge. 



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