Notices respecting J¥eio Books. 303 



and others confined between drift-ridges. Many lake-areas have 

 been limited, or qnite filled np, by sedimentary deposits, now 

 forming valuable land. (3) Water-supply by springs and wells, 

 also local water-power, and changes of drainage, especially by the 

 felling of timber, are duly noticed. 



Chapter III. treats of the Native Yegetation, dividing itself into : — 

 A. Upland Vegetation ; B. Marsh Vegetation ; C. Intermediate 

 groups. The relation of rocks and soils to the local vegetation is 

 carefully kept in sight. Soils and their origin form the interesting 

 matter of Chapter IV. ; and Chapter V. has a full treatment of the 

 Quaternary formations, or Drift, of the district under notice. In 

 the first place, (1) morainic ridges, and (2) boulder-clay or till, are 

 described as " Primary Drift ;" secondly, the sands and gravels of 

 lake-beaches and lacustrine deposits of clay are described as 

 " Secondary or modified Drift ;" thirdly, many local deposits due 

 to streams and small lakes are referred to. Glacial movements and 

 the results of ice-action come within the subject-matter of these 

 pages; and the Kettle Eange, with its "Pot-holes " or " Sinks" and 

 its mounds and ridges of sand and gravel, is particularly described. 

 The Kettle Range proper is parallel with Lake Michigan, but con- 

 tinues south, west, and north, in an elliptical curve, as the boundary 

 line of a great radiating ice-drift from the north-east. In its 

 eastern portion it has been accumulated between the above men- 

 tioned and another, similar, parallel, south-west driftage, which 

 came along the Lake Michigan area. The economic uses of the 

 Drift-deposits for bricks, pottery, &c, and the shell-marl and peat 

 of obliterated lakes, are also treated of. 



Four chapters are next occupied with a description of the geolo- 

 gical formations which constitute the substructure of Eastern Wis- 

 consin, namely : — (1) Devonian : the Hamilton group. (2) Upper 

 Silurian: the Lower Helderberg and the Niagara. (3) Lower 

 Silurian: the Cincinnati, Galena, Trenton, St.-Peters, Lower Mag- 

 nesian, and Potsdam formations. (4) Archcean: the Huronian and 

 Laurentian. 



In Part III. of the volume we have the " Geology of Central Wis- 

 consin," by Roland D. Irving (pp. 407-636). This tract comprises 

 an area of about 10,000 square miles, and exhibits Laurentian, 

 Huronian, Primordial (namely, 1. Lower or Potsdam Sandstone, 

 and 2. Beds of Passage, as the Mendota Limestone and Madison 

 Sandstone), Canadian (namely, 1. Lower Magnesian Limestone, and 

 2. St.-Peter's Limestone), and Trenton (namely, 1. Trenton Limestone, 

 2. Galena Limestone) groups (see Table, with details, at p. 460). 

 Above these Lower Silurian rocks are Quaternary deposits of the 

 Glacial, Champlain, and Recent formations. This report is illustrated 

 with numerous and especially neat sections and plans, with the pro- 

 portional scales systematically given. Among the many interesting 

 details supplied, the definition and description of the western 

 portion of the Kettle Range, consisting of morainic drift (pp. 615 &c), 

 alluded to above, are especially noteworthy. To this Report is an 

 Appendix, by Charles E. Wright, on the Microscopic Lithology of a 



