Geology and Mineralogy . 83 



Practical Corona Calculation for Transmission Lines " ; and " Prac- 

 tical Considerations in the Design of Apparatus where Solid, 

 Liquid and Gaseous Insulations Enter in Combination." The 

 appendix (pages 238 to 256) comprises a large number of tables 

 of numerical data pertaining to corona losses. The graphs and 

 diagrams are clear-cut and the reproductions of photographs are 

 excellent. In general, special attention seems to have been given 

 to making the text as accurate, useful and practical as possible. 

 Chapter VIII, on the electron theory, alone marks an exception. 

 For example, on page 193 may be found the following slips : 

 " . . . a wire-carrying current"; "Each ion in a gas acts' as 

 nuclei . . ." ; " Ion is a general term used for . . . electrons. . . ." 



h. s. u. 

 9. The Radium- Uranium ratio in Carnotites; by S. C. Listd 

 and C. F. Whittemore. Bureau of Mines, Tech. Paper 88 

 (Mineral Tech. 6). — The authors have carried through an investi- 

 gation of the carnotite of Colorado and Utah as to the radium- 

 uranium ratio. The results obtained can best be given by 

 quoting at length the summary with which the paper closes: 



1. Samples of carnotite representing large quantities of ore (a 

 few hundred pounds to several tons) show a radium-uranium ratio 

 identical with that of pitchblende (3-33X10 -7 ); this ratio is also 

 in accord with the value calculated from radiation data. 



2. Samples from small quantities of ore (hand specimens up to 

 a few pounds) tend to exhibit abnormal ratios. In one instance 

 the ratio was as low as 2-48 X10 -7 , and in another as high as 

 4-6 X10- 7 . 



3. The most plausible explanation for these abnormal ratios 

 seems to be that of transposition of radium within the ore bed, 

 producing local differences which are equalized in lar^e samples. 



4. The " emanating power " of carnotite is high, and varies 

 from 16 to 50 per cent. 



5. In order to obtain concordant results by the Boltvvood 

 emanation method it was found desirable to determine the ema- 

 nation liberated by solution in the same sample from which the 

 emanating power had just been determined, thus making the two 

 determinations strictly " complementary." 



6. Radium may be easily determined in one operation by the 

 emanation method, either by solution or by ignition from tubes 

 in which it has been sealed for one month to reach equilibrium. 



7. In contrast with the success of the solution and the ignition 

 methods for de-emanating carnotite, the method of fusion with 

 sodium and potassium carbonates and the fusion-and-solution 

 method both gave low results and were abandoned. 



II. Geology and Mineralogy. 



1. Climate and Evolution /by W. D. Matthew. Ann. New 

 York Acad. Sci., vol. xxiv, 1915, pp. m-318, figs. 1-33.— The 

 title of this important work does not convey the intent of the 

 author and should have been "The geographic dispersal of 



