300 



SCIENCE. 



[Vol. V., No. 114. 



Superior geology. To the class of formations 

 later than the Keweenawan, he refers the fos- 

 siliferous Cambrian sandstone of the Missis- 

 sippi valley, and the horizontal sandstones of 

 the Superior basin, known in local geology 

 as the 'eastern' and 'western' sandstones. 

 To the series of older formations he refers the 

 Animikie group, the original Huronian, and 

 the Penokee, Marquette, and Menominee Hu- 

 ronian groups. The fossiliferous sandstone of 

 the Mississippi valle}' (Potsdam) he confidently 

 considers later than the Keweenaw series, 

 because it unconformable overlies it, with 

 evidence of great intervening erosion. The 

 ' eastern ' and ' western ' sandstones also are 

 held to be newer, because they adjoin the 

 Keweenaw series by unconformable contacts 

 associated with fault-lines. These three sand- 

 stones he refers to essentially the same horizon, 

 — the Potsdam, or its immediate downward 

 continuation. In support of these views, he 

 cites a large array of specific evidence, and 

 gives precision to his discussion b} T maps and 

 diagrams. The older formations named are 

 separated from the Keweenawan on the 

 grounds of unconformable relations, and dis- 

 cordance of character. 



The stratigraphical discussion is fittingly 

 closed by a sketch of the Lake-Superior syn- 

 clinal. The existence of a downward flexure 

 embracing the western part of the basin was 

 long since made known by Foster and Whitney. 

 Professor Irving and his Wisconsin colleagues, 

 a few }*ears since, determined its south-westerly 

 extension into the borders of the Mississippi 

 basin. The author now makes an important 

 extension eastward so as to embrace nearly all 

 of the lake's area, the trough assuming a 

 curved, rudely reniform contour. 



The monograph is closed b}* a chapter on the 

 copper deposits, which were, however, not 

 special subjects of investigation. 

 • The treatment throughout is candid and able. 

 There is a close adherence to facts, and the 

 conclusions that legitimately flow from them. 

 The memoir is a valuable contribution to gen- 

 eral geology. The horizon of which it treats 

 has long lain under a cloud of obscurity*, if 

 not of actual chaos, in Europe as well as in 

 America. The distinct differentiation of the 

 formations of one important field cannot fail 

 to aid in the study of all others. When equally 

 explicit descriptions of other regions involving 

 this horizon shall be at command, we shall 

 doubtless be on the threshold of agreement as 

 to its taxonomic place and value. Present dis- 

 agreement is largely an expression of imper- 

 fect knowledge and provincial study. 



WORLD-STUFF. 



' Whence came this world ? ' and ' Whither is 

 it going ? ' are questions of never-tiring interest 

 to mankind, — questions upon which they have 

 pondered for long ages, and which are still 

 unsolved. Where is the man who, without a 

 shudder, can turn from the beautiful life around 

 him, and in fancy contemplate a cold, cheer- 

 less, dark, lifeless condition of the world to- 

 wards which we have every reason to believe 

 it is tending? 



In the book before us we have an effort made 

 to weave the various speculations of others, re- 

 garding the evolution of the universe, into a 

 continuous and harmonious whole lry an admix- 

 ture of the author's own ideas. Professor 

 Winchell is well known from his past efforts 

 to popularize science, and for his speculative 

 tendencies ; and perhaps he, of all American 

 writers, is best fitted to popularize a subject 

 like the one he has chosen, and commend it 

 to the interest and attention of the masses. 

 The work is to be judged rather by its success 

 or failure as a popular presentation of the sub- 

 ject, than as an original contribution to cosmical 

 science. In either respect, the book is disap- 

 pointing ; for our author, instead of keeping in 

 a field in which he has perhaps no superior in 

 America, has attempted a middle ground. He 

 has written so that his treatise occupies a higher 

 plane as a scientific treatise than his previous 

 books, although, as is the tendency of all spec- 

 ulative minds, the presentation of theories has 

 been mistaken for the presentation of evidence 

 and proof. Again : as a popular presentation 

 of the subject, the work falls below the other 

 books of the author, so far as we are acquainted 

 with them, and doubtless many portions will 

 be considered by its readers as dry and pedan- 

 tic. On the other hand, the work shows in 

 many parts a mode of presentation of certain 

 difficult questions that is well worthy the care- 

 ful study of the majority of our scientific 

 writers who have any T desire that their readers 

 should understand what they are writing about. 



The author holds that the dust and iron 

 globules found in the depths of the sea and on 

 the mountain-tops are of meteoric origin, — a 

 veritable w'orld-stuff, pervading all space, — 

 and that by and from this stuff world-systems 

 are evolved. He supposes that a tendency for 

 immense amounts of these dust particles to 

 associate about a common centre leads to the 

 formation of nebulous clouds, which, from a 



World-life ; or, Comparative geology. By Alexander 

 Winchell, LL.D., professor of geology and paleontology in 

 the University of Michigan. Chicago, Griggs, 1883. 21+642 p. 

 12°. 



