328 Scientific Intelligence. 



9. Modern Theory of Physical Phenomena; by Augusto 

 Rigiii. Authorized Translation by Augustus Trowbridge. 

 New York, 1905. (The Macmillan Co.) 



Pa Theorie Moderne des Phenomenes Physique ; par Augusto 

 Right. Traduction libre sur la 2 e edition italienne par Eugene 

 Neculcea. Editions de "L'Eclairage Electrique." 



These two translations bear witness to the richly deserved pop- 

 ularity of Professor Righi's little book. It is without question 

 the best popular exposition that we have of the modern point of 

 view which explains the phenomena of electricity, radio-activity 

 and optics in terms of the electron. The translation is very well 

 done and the book can be recommended unqualifiedly to the gen- 

 eral reader who desires to get in a simple and non-technical form 

 the gist of the epoch-making developments of the theory of elec- 

 trons. L. p. w. 



II. Geology and Mineralogy. 



1. Red Beds of Southwestern Colorado and their Correlation; 

 by Whitman Cross and Ernest Howe. Bull. Geol. Soc. 

 Amer., xvi, Dec, 1905, pp. 447-498, pis. 82-85. — This is the 

 most important paper thus far published on the " Red Beds " of 

 the Rocky Mountain region, and should be read in connection 

 with Stanton's paper on the Morrison formation published in 

 "The Journal of Geology," xiii, 1905, pp. 657-669. All of the 

 Red Beds regions, from northeastern Arizona north to central 

 Wyoming and east to the Front Range of Colorado, are reviewed 

 by Dr. Cross. As his conclusions are of the first importance, his 

 " summary" is repeated here in full. It is as follows : 



" 1. A marked angular unconformity is exhibited near Ouray, 

 Colorado, between a well defined fossiliferous horizon of the 

 Dolores Triassic formation and an extensive section of Paleozoic 

 beds, including the Cutler Permian and the Hermosa Pennsyl- 

 vanian formations. 



" 2. The Ouray unconformity is evidence of a stratigraphic 

 break, of as yet unknown importance, in the midst of the Red 

 beds of western Colorado. There are reasons to suppose that 

 this hitherto unrecognized break is widespread and explains 

 many discordant features of various Red bed sections, not only 

 in Colorado, but in the adjacent Plateau province. 



" 3. The fossiliferous horizon of the Dolores formation, occur- 

 ring above the unconformity noted, has been traced down the 

 Dolores and San Juan valleys into the Plateau province. The 

 sections of the mountain and plateau districts are comparable in 

 many ways. 



" 4. A vertebrate fauna, similar to or identical with that of the 

 Dolores formation, has been found at widely separated points in 

 New Mexico, Arizona, Utah, Wyoming, and Colorado, and pale- 

 ontologists regard it as clearly of upper Triassic characteristics. 



