376 REVIEWS 
of a mine and mill at Roxbury Falls, Conn. Feldspar showed an in- 
crease of about 20 per cent in value of product, the total reaching half a 
million dollars for the first time. Maine produced more than one-third 
of the total value, with only a little more than one-fourth of the total 
tonnage. The value of the year’s production of feldspar and quartz 
amounted to less than three quarters of a million dollars. 
A. D. B. 
Denudation and Erosion in the Southern Appalachian Region and the 
Monongahela Basin. By LEONIDAS CHALMERS GLENN. 
U:S. GeolsSurvey. Professional Paper) 72." 10r1-) sepa aye 
Haeg, Gees VOLS, Wit. 
This report presents a summary of the results of an examination made 
for the purpose of studying the effect of deforestation and consequent 
erosion of the steep mountain slopes on geologic, hydrologic, and eco- 
nomic conditions, both in the mountain region itself and in the sur- 
rounding area through which the streams flow. The area under 
consideration contains the largest and most valuable hardwood area 
in the United States. 
The removal of forests by unscientific lumbering, by forest fires, for 
mining, and for agricultural purposes leaves the slopes in a condition 
to be eroded easily, making the run-off of rains greater and more sudden, 
causing floods that do great damage in the valleys. The remedies 
suggested are: (1) putting the cleared slopes into grass or terracing 
them, (2) preventing the clearing of steep slopes, and (3) the prevention 
of forest fires that usually follow in the wake of lumbermen. 
The existing conditions are described for each river basin, and special 
consideration is given to the large floods of recent years. At the end 
in tabular form, the various river basins are classified according as their 
streams are in (1) timbered basins where little damage is done by floods; 
(2) cleared basins where floods do much damage; (3) cleared basins where 
floods do little damage because the soil is porous or else the clearings are 
largely in grass; and (4) timbered areas in which the tributaries have 
damaging floods due to logging on steep slopes. ING 105. 18 
Characteristics of Existing Glaciers. By WILLIAM HERBERT Hoss. 
New York, ro11. Pp. xxiv+301; figs. 140; pls. 34. 
In this work emphasis is laid on the great difference in the laws 
governing mountain glaciers and bodies of inland ice, and on the geologi- 
cal effects of the two classes of glaciers. The dissimilarity in the 
