ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly to the editors. 

 Each of the scientific bureaus in Washington has a representative authorized to 

 forward such material to this journal and abstracts of official publications should 

 be transmitted through the representative of the bureau in which they originate. 

 The abstracts should conform in length and general style to those appearing in 

 this issue. 



GEOGRAPHY. — The Navajo country, a geographic and hydrographic 

 reconnaissance of parts of Arizona, New Mexico, and Utah. Her- 

 bert E. Gregory. U. S. Geological Survey Water-Supply Paper 

 380. Pp. 219, with maps, sections, and illustrations. 1916. 

 The Navajo country includes 25,000 square miles of arid and semi- 

 arid lands occupied by about 32,000 Indians and 500 whites. Only a 

 small pari of it has previously been described. The report, therefore, 

 includes an unusually full treatment of geography under the heads: 

 historical sketch, geographic provinces, climate, soil, flora, fauna, min- 

 eral wealth, population, and industries. Many additions have been 

 made to existing maps, and the list of geographic terms has been re- 

 vised. Since the future of the country depends upon the solution of 

 the problem of water supply, particular attention was given to the oc- 

 currence of surface and ground waters. The Colorado and the San 

 Juan rivers are perennial; all others are intermittent or ephemeral, but 

 their flood waters may be utilized by construction of suitable works. 

 Manx- springs and seeps may also be developed. The sinking of wells 

 in deposits of various types is recommended, and the parts of the region 

 favorable for artesian flows are indicated. Except for structure sec- 

 tions and maps and the description of water-bearing beds, the report 

 contains little strictly geological material. Such matter will appear in 

 Professional Paper 93, now in preparation. H. E. ('. 



GEODESY. — Precise leveling from Reno to Las Vegas, Nev., and from 



Tonopah J unction, Nev. to Laws, Cat. H. G. Avers and G. D. 



Cowie. U. S. Coast and Geodetic Survey, Special Publication 



No. 39. Pp. 49. 1916. 



This publication gives the results of a line of levels run in 1915 



along the railroads between Reno and Las Vegas, Nevada, and between 



132 



