602 



SCIENCE. 



LN. S. Vol. III. No. 



The appearance of the book is in every way 

 faultless. J. Christian Bay. 



Iowa State Board of Health, 



SCIENTIFIC JOURNALS. 

 THE AMERICAN GEOLOGIST, APRIL. 



Apparent Anomalies of Stratification in the Post- 

 ville Well: By Samuel Calvin. A recently 

 bored well in northeastern Iowa shows a re- 

 markable and unusual thickness of shaly ma- 

 terial in the St. Peter Sandstone. Caverns are 

 frequent in this unconsolidated and easily 

 eroded sandstone, and the author suggests that 

 in this case a cavern was formed in the St. 

 Peter sandstone and it was afterward filled by 

 descending waters with material from the shaly 

 members of the overlying Trenton. 



Englacial Drift : By W. O. Crosby. In the 

 longest paper of this number, Prof. Crosby 

 presents a very thorough discussion of the 

 drift which was transported in the lower part 

 of the thick Pleistocene ice sheets, comparing 

 them with the Malaspina Glacier and with the 

 present ice sheet of the interior of Greenland. 

 To designate the drift so enclosed in glaciers 

 and ice sheets, Chamberlin proposed the term 

 englacial, but he supposes that this part was of 

 small amount in comparison with the drift 

 dragged and pushed along beneath the ice as 

 its ground moraine. Crosby shows by the 

 almost universally glaciated surface of the bed- 

 rocks beneath the drift, excepting near the 

 borders of the drift-bearing areas, that the ice 

 sheet gathered into its lower part all the pre- 

 glacial residuary soil and alluvium, until the 

 base of the ice, thickly charged with englacial 

 drift, wore into the hard underlying rocks. 

 With the return of a warm climate, during the 

 Champlain epoch, causing the final recession 

 and departure of the ice. Prof. Crosby thinks 

 that the rapid surface melting was accompanied 

 also by much melting of the base of the ice 

 sheet, whei'eby much of the previously engla- 

 cial drift was deposited as subglacial till. It 

 becomes, therefore, difficult to discriminate the 

 finally subglacial deposits from the portion of 

 the drift which continued to be englacial until 

 the surface melting or ablation at last exposed 

 it as superglacial till. The origin of the modi- 

 fied drift, or stratified gravel, sand and clay, 



brought by streams of water from the drift- 

 laden ice. Prof. Crosby ascribes in its larger 

 part to subglacial drainage, rather than to the 

 superglacial streams which Upham has re- 

 garded as the chief agency of derivation of 

 these beds during the mainly rapid final retreat 

 of the ice. 



Further examination of the Fisher Meteorite: 

 By N. H. Winohell. Further careful study 

 of this interesting meteorite shows that it con- 

 tains considerable glass, the mineral asmanite 

 (tridymite), and very probably the mineral 

 maskelynite. 



Preliminary Notes on Studies of the Great Lakes 

 made in 1S95 : By F. B. Taylor. The author 

 states that his explorations and studies during 

 1895 lead him to doubt his former reference of 

 the high shore lines about the upper great lakes 

 of the St. Lawrence to marine submergence at- 

 tending or following the close of the Ice Age, 

 instead of which he now concludes that prob- 

 ably all these shores belonged to vast lakes held 

 by the barrier of the waning ice sheet. He as- 

 serts, however, that the glacial Lake Warren, 

 according to his exploration of its shores, was 

 limited to the basin of Lake Erie and the 

 southern part of the Huron basin, outflowing 

 by the Pewano channel, southwest of Saginaw 

 Bay, to the glacial Lake Michigan. The very 

 high shores around Lake Superior and the 

 northern part of Lake Huron and Georgian 

 Bay, he attributes to the later Lake Algonquin, 

 with outlet by a river flowing to the south and 

 east along the present bed of Lake Erie. 



In an editorial comment by Mr. Warren 

 Upham, referring to Mr. Taylor's paper, it is 

 suggested that only the highest beach which 

 had been attributed to Lake Warren in the 

 Erie basin may represent the Pewamo outlet, 

 and that later stages of Lake Warren, flowing 

 past Chicago to the De's Plaines and Illinois 

 rivers, probably formed the Arkona and Forest 

 or upper or lower Crittenden beaches, and the 

 high shores of the Georgian Bay region, and 

 also of Lake Superior, excepting those of its 

 western part belonging to an earlier glacial 

 lake. 



THE MONIST, APRIL, 1896. 



Prof. Mach describes a method of using 

 Eontgen's X-rays for obtaining stereoscopic 



