"~~(Preliminary) concerning ex p 10 ration sand s u r v e y s princit:.
1. paHy in Ne v a da and Ari Z 0 n a. Prosecuted in accordance with 

(JIO' 
paragraph 2, special orders No. 109, War Department, March 18, 
1871, and letter of instructions of March 23, 187I,from Brigadier 
General A. A. H u m p h r e y s, chief of engineers. Conducted under 
the immediate direction of 1st Lieut. George M. Wh e e 1 e r, corps 
of engineers. 1871. (I Karte.) 4;. Washington 1872.