248 Scientific Intelligence. 



arising from the movements and deposits of the successive 

 advances of the ice front in the Lake Michigan region. Not 

 only detailed study but more refined methods of investigation 

 were demanded, and the development of these methods will be 

 useful in all future glacial work. The various drift sheets are 

 described in detail under the following heads : 1. The Illinoian 

 Drift Sheet — the most extensive in the region, which was preceded 

 by an interval of deglaciation (Yarmouth) and followed by the 

 Sangamon interval of deglaciation. 2. The Iowan Drift Sheet, 

 in the discussion of which the whole loess problem is gone over 

 and conflicting views compared, without however arriving at a 

 definite general conclusion as to the origin of the loess. The 

 Iowan deposits are overlaid in places by the " Peorian soil " of 

 another interval of deglaciation. 3. Two Wisconsin Drift Sheets 

 complete the series. 



Perhaps the most generally interesting part of the monograph 

 are chapters xi and x-ii, dealing with beaches of Lake Chicago 

 and the Chicago outlet and with the many cases of reconstructed 

 drainage throughout the drift-covered area. Each stream is 

 treated separately and the past and present conditions of its 

 drainage basin is discussed. In Chapter xiv all the reliable well 

 records of Illiuois are given and conclusions drawn as to charac- 

 ter of soil, relation of drift to water supply, etc. From the well 

 data and from comparison of the drift areas to adjoining driftless 

 areas the average thickness of the Illinois drift sheet is given as 

 100 to 130 feet," h. e. g. 



3. The Geography of the Region about Devils Lake and the 

 Dalles of the Wisconsin with some notes on its Surface Geology; 

 by Rollin D. Salisbury and Wallace W. Attwood. Wis- 

 consin Geol. and Nat. Hist. Survey, Bulletin No. 5, pp. 1-146. 

 85 plates and illustrations. — This bulletin of the Wisconsin Sur- 

 vey begins an educational series designed primarily for use in the 

 schools. It marks the beginning of a plan to make the work of 

 the geological surveys directly useful to all intelligent people of 

 a state instead of to the few specialists. The volume was evi- 

 dently prepared by skillful teachers, for the region chosen for 

 description is clearly marked and typical and interesting and the 

 plan of presentation is that of the most successful instructors. 

 Part I is a description of the topography of the area — the 

 quartzite ridges and the sandstone plains. Part II deals with 

 the history of the topography. The origin of the rocks which 

 show themselves at the surface is explained and their scenic fea- 

 tures which result from erosion are described. The glacial period 

 and its effect on topographic form is treated of easily. In con- 

 nection with each division of the subject there is given just 

 enough theoretical matter to put the abundance of local facts in 

 proper perspective. The volume contains no geological facts 

 regarding this interesting region which have not been published 

 before, but it is timely and valuable as a plan for presenting a 

 geographical subject to schools and as a suggestion to state sur- 

 veys. H. E. G. 



