REVIEWS 721 



use of "the former" and "the latter," the English is good. The author 

 uses words denoting time where place or number is involved in a 

 monotonously regular way. The book must contain over a thousand 

 cases of such misused words. 



The origin and derivation of technical terms introduced throughout 

 the book is a feature of much value. This point is somewhat dis- 

 counted, however, by the use of some of these terms before they have 

 been explained. For instance, the terms "travertine," "strike," 

 "eskers," "basal conglomerate," "feldspars," "scoriaceous," "stoping," 

 "schistose," "systems," "fauna," "phylum," are all introduced in 

 advance of their explanation, and some of them are used repeatedly with- 

 out explanation. 



The scientific and pedagogical character of the book is marred by 

 a certain odd looseness and indefiniteness of statement, which must 

 militate against clear thinking and expression on the part of the student. 

 On p. 298 lava is said to be "molten" rock; on p. 300 it is made clear 

 that lava is rock dissolved rather than melted; and on p. 329 it is stated 

 that igneous rocks "have consolidated from a state of fusion." The 

 first part of the last sentence on p. 253 is true only when the surface of 

 the ground is flat or nearly so. In Part II the terms "system," "group," 

 "period," "era," etc., are defined, but these terms are used in various ways 

 on pp. 383, 389, 392, 401, 384, 477, and 574. On pp. 89 to 92 various 

 points are numbered for the sake of definiteness, but points 4 and 5 

 are quite similar to point 1; in the same way on p. 128, 5 and 1 are 

 practically identical. On pp. 199 and 200 there are three statements, 

 each of which appears to be contradictory to the other two. Some of 

 the geography is ambiguous, especially that which refers to the western 

 portions of the United States. The author of the book does not seem 

 to realize the magnitude and importance of the area west of the Mis- 

 sissippi River. An illustration is found on p. 403, where the Cambrian 

 rocks are carefully located in the East and then are said to be exposed 

 "in portions of the West." On p. 658 the exact meaning of the figures 

 at the close of the second paragraph is not clear. Illustrations of this 

 looseness and indefiniteness are found on at least thirty-three pages of 

 the book. 



Although most of the topics are treated adequately, an effort to 

 obtain brevity has led to incomplete treatment of antecedent streams, 

 p. 102, of tides, p. 202, of the economic importance of metamorphism, 

 p. 351, of the Planetesimal Hypothesis, pp. 386 and 387, of the physical 

 problems of the Ordovician, pp. 418 to 434, of the Red Beds, p. 511, of the 



