192 Scientific Intelligence. 



graphic surveys $300,000 was appropriated, for geologic surveys 

 $200,000, as during the previous year. The entire appropiation 

 for the year was $1,590,680. j. b. 



y/ 2. Fifth Biennial Report. State Geological Survey of North 

 Dakota * A. G. Leonard, State Geologist. Pp. 278, plates xxx. 

 Bismarck, North Dakota. — The purposes of the reports of the 

 survey are educational in the teaching of physical geography 

 and elementary geology, and developmental of the economic 

 resources of the state. In this volume, besides the administrative 

 report, there are papers on the geology of southwestern North 

 Dakota with special reference to the coal, by A. G. Leonard ; the 

 geology of northeastern North Dakota with special reference to 

 cement materials, by John G. Barry and V. J. Melsted ; the 

 geological history of North Dakota, by A. G. Leonard ; the 

 Bottineau gas held, by John G. Barry, and a paper on good roads 

 and road materials, by W. H. Clark. The papers in general 

 meet well the purposes for which they are planned and the sur- 

 vey by such a report demonstrates its value to the state. The 

 paper on the geological history of North Dakota could, however, 

 have been improved in a number of particulars. 



It was prepared for the use of schools and the general reader,. 

 yet there is no statement in it of the fundamental conception 

 that geologic time embraces tens of millions of years. Yet 

 without such discussion the general reader is apt to preserve the 

 inherited notion that time is antediluvian and postdiluvian and 

 the whole embraced in some thousands of years. This, however, 

 is a minor point in comparison with definite errors retained from 

 an earlier period in geology. For example, it is sweepingly 

 stated that "granites are examples of Archean rocks." Whereas 

 they are now known to occur as massive intrusive rocks of any 

 age up to middle Tertiary. Further, it is stated "that the oldest 

 part of the continent, that which was the first to be raised above 

 the sea, was a U-shaped land mass, the two arms of the U enclos- 

 ing Hudson Bay. At the beginning of the Paleozoic Era by far 

 the greater part of our continent, with the exception of the above 

 land, was beneath the sea." This statement may be compared 

 with Walcott's well-founded conclusions, published in 1891, that 

 the area of the pre-Cambrian Algonkian continent was larger 

 than at any succeeding period until the Mesozoic, and that the 

 Cambrian sea did not begin to invade the great interior con- 

 tinental area until late Middle Cambrian time. It is true that 

 these and other important conceptions have not been properly 

 emphasized in many text-books, but that cannot be regarded as 

 good reason for their further perpetuation. Their importance in 

 geologic theory is, furthermore, such as to warrant calling atten- 

 tion to their occurrence in this report. The idea, however, of 

 publishing in state reports popular expositions of geologic struc- 

 ture and history, as is here done, is a most valuable one from the 

 educational point of view, and one which state surveys have 

 largely neglected. J. b. 



