264 The American Geologist. October, 1904. 
Tbe folio also clearly shows the unexpected folding which the rocks 
of this quadrangle have undergone. Attention was first directed to this 
folding by professor Prosser in 1894, which had been overlooked by 
other geologists whd^'^supposed that the rocks of central Kansas had a 
nearly uniform dip of small amount to the northwest. In an earlier 
section along the Couonwood river the geologist failed to recognize 
the reappearance of the Cottonwood limestone in ascending the river, 
due to an anticlinal fold, and so it was given a new numlser and re- 
garded as a distinct and higher limestone. 
Radio- Activity by E. Rutherford, MacDonald Professor of Physics, 
McGill University, Montreal. University Press, Cambridge, 1904, 
399 PP- 
Amidst the flood of papers, often immature and incomplete, relat- 
ing to radio-activity, which have appeared within recent years, it is a 
distinct pleasure to meet with one in which the subject is treated in a 
comprehensive as well as calm and judicial manner. In the work issued 
under the above title professor Rutherford lias l>rouglit together the 
available infomiation relating to the so-called radio-active minerals 
in the form of a somewhat brief summary of twenty-seven pages. The 
remainder of his book is given up to a discussion of the Ionization The- 
ory of Gases; Methods of Measurement; Nature of the Radiationsi; 
Rate of Emission of Energy ; Properties of the Radiations ; Continu- 
ous Production of Radio-active Matter; Radio-active Emanations; Ex- 
cited Radio-activity ; Radio-active, Processes ; and Radio-activity of the 
Atmosphere and of Ordinary Materials. Abundant references and 
footnotes serve to make the book a very satisfactory bibliography of 
the subject. 
Incidental reference may be made to an earlier work by Dr. Philip 
Browning, of Yale University, entitled An Introduction to the Rarer 
Elements, which forms a very convenient supplement to the work of 
Rutherford, above noted. This last, aside from giving a brief historical 
sketch of each of the so-called rare elements, mentions the natural 
minerals in which it occurs, the tj'pical compounds formed, their prop- 
erties, and miethod of extraction. G. P. M. 
MONTHLY AUTHOR'S CATALOGUE 
OF AMERICAN GEOLOGICAL LITERATURE 
ARRANGED ALPHABETICALLY. 
ABBE, CLEVELAND, JR. 
Earthquake i-ecords from Ag-ana, island of Guam. (Ter. Mag. 
Atnio.s. Klec, June, 1904, pp. 81-85.) 
ANON. 
Preliminary report on the buildini;- stones of Nevada. iuLluding: 
a brief chapter on road metal. lUill. Dept. Geol. and Min.. I^niv. 
Nevada, vol. 1, p:\rt 1, June, 1904. Not paged. 
