634 abstracts: geology • 



GEOLOGY.— Gu/de book of the Western United States, Part C. The 

 Santa Fe Route. N. H. Darton and others. U. S. Geological 

 Survey Bulletin 613. Pp. 194, maps and illustrations. 1915. (For 

 sale by the Supt. of Public Documents, Washington, D. (\ 

 Price $1.) 

 The average busy American is prone to regard the journey across 

 the Great Plains of the Middle West and the arid stretches of New 

 Mexico and Arizona, as an enforced tedium to be mitigated as far as 

 possible by slumber, magazines, or the ''smoker." Only some unusu- 

 ally picturescjue feature stirs him to a real interest in his surroundings. 

 Travel for the purpose of understanding the country traversed rather 

 than as a means of getting from city to city is an art less developed here 

 than abroad. The purpose of this guide book of the Santa Fe Route 

 is to make the 1800 miles between Kansas City and Los Angeles in- 

 teresting and educating to the intelligent traveler, by explaining in non- 

 technical language the meaning of the things that are visible from the 

 car window. Emphasis is placed upon the meaning of the scenic fea- 

 tures of the landscape, as is natural in a publicatioji emanating from the 

 Geological Survey, but many features of agricultural or of botanical 

 interest, such as the peculiar floral features of the desert, are also de- 

 scribed, and the history of human endeavor in the "winning of the 

 west" receives a just share of attention. 



The explanation of such striking natural features as the petrified 

 forest in Arizona, the volcanic cones near Winona, Arizona, and great- 

 est of all, the Grand Canyon, will be particularly welcomed bj^ trav- 

 elers. Of great human interest are the descriptions and pictures of 

 Hopi and Navajo Indian villages of the "Painted Desert." The jour- 

 ney through some of the less picturesque regions is enlivened by excur- 

 sions into the geologic past whose gigantic reptiles are pictured from 

 authoritative restorations by Charles R. Knight. E. S. Bastin. 



GEOLOGY. — The fractional precipitation of some ore-forming com- 

 pounds at moderate temperatur-es. Roger C. Wells. U. S. 

 Geological Survey Bull. 609. Pp. 46. 1915. 

 The experiments described in this bulletin were made to aid in 

 elucidating the chemistry of ore deposition. They yield as their 

 immediate result the order of solubility of the compounds of each of 

 the classes investigated — sulfides, hydroxides, carbonates, and sili- 

 cates. The results with the silicates are really those due to hydroxides, 

 since the silicates are so completely liydrolyzcd in aciueous solution, 



