SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 167 



PUBLICATIONS REVIEWED. 



The Cementing Power of Road Materials. By Logan Waller Page 

 and Allerton S. Cushman, of Division of Tests, U. S. Dept. Agrie., Bur. 

 of Chem. Bull. No. 85. Washington, 1904. Pp. 24, 1 PL— A timely and 

 most valuable contribution to an important subject by worthy experi- 

 menters. The methods of testing are clearly described and illustraced 

 by cuts in the text. It is demonstrated by their work that the binding 

 quality of road metal is not due to particular chemical elements, but 

 to the degree of hydration. Therefore, it is not practicable to determine 

 the relative values of different rocks, in this i-espect, by lithologic exam- 

 ination or by mere chemical analysis. A table of tests already mad<3 

 from various widely scattered localities in the United States affords 

 interesting suggestions, but it is too early to draw wholly reliable 

 conclusions as to the geographic distribution of the most suitable road- 

 making materials. Engineers have heretofore given far too little study 

 to this important subject. 



The "Institute Geologico" of Mexico continues to send out noces. 

 and papers of scientific interest. Vol. I, No. 4 contains a somewhat 

 exhaustive study of a theory upon which Dr. Almarez had predicated 

 the probability of the existence of petroleum in Aragon. Sr. Villarello 

 critically dissects the author's reasoning and concludes that it is in- 

 conclusive and inapplicable, and that no evidence of the occurrence' of 

 oil there in commercial quantity has been produced. An excellent plate 

 of a large meteorite is given by Dr. Angermann, who describes it, with 

 an interesting account of its discovery, in 1863, and its announcement 

 scientifically, in 1876 and 1889. Dr. Henry A. Ward, of Eochester, N. Y., 

 had it exhumed and he more fully described it in 1902. In Vol. I, No. 5 

 (titled elsewhere in full), valuable notes on the earthquake of 16th 

 Jan'y, 1902, in Guerrero, are given from studies on the ground by Drs. 

 Bose and Angermann, both diligent workers, whose labors have been 

 earlier announced in the "Parergones. " The article on an asbestiform 

 mineral, in the same issue, by Senor Villarello, an engineer of repute, 

 is very thorough. He concludes that this is an aluminum hydrosilicate, 

 allied to the kaolins, approximating montmorillinite, with some physical 

 features of asbestos, from which it materially differs in composition 

 and properties. It does not bear out the hope raised for 'its application 

 in the arts as a perfect substitute for asbestos, although it has limited 

 usefulness in that direction. 



In Dr. Meniam's description of "A New Marine Reptile From the 

 Triassic" of Shasta County, there are some points of great technical 

 interest and bearing upon the development of vertebrate types. But, 

 more than this, we have in the discovery and publica;tion a fitting 

 tribute of Miss A. M. Alexander, "who has not only contributed gener- 

 ously to the financial support of the work on the vertebrates of the 

 Marine Triassic, but was herself the discoverer of the type specimen," 

 which has been named in her honor, Thalattosaurus alexandrae. 



Cost of Pumping for Irrigation, in ten examples selected by Pro- 

 fessor Woodward, of the University of Arizona, varied from less than 

 4 cents to more than 29 cents per acre-foot of water raised one fooc. 

 The best results are due to the application of brain power to the 

 problem of adapting the machinery to the duty at hand. In ocher 

 words, the investigation once more emphasizes the costliness of saving 

 engineers' fees at the start. One plant, with wood at lowest cose per 

 unit, had the greatest cost per unit of power developed, and the great- 

 est cost for attendance, lubricating, repairs, etc., although the duty 



