124 The American Geologist. February, 1903. 
of magnetic declination in .he Unit.^d States and outlying territories 
reduced to Jan. i, 1902, and h}' descriptions of the magnetic stations. 
N. H. w. 
lozva Geological Surz'cy, J'olitiiic XII, Annual Report, 1501, zAth ac- 
companying Papers. Samuel Calvin, State Geologist ; A. G. Leon- 
ard, Assistant State Geologist. Pages 511; with 6 folded maps. 11 
plates, and 78 figures in the text. Des Moines, 1902. 
The administrative report of the state geologist, in pages 11-27, shows 
that the Survey had been completed in fifty-three counties, and was in 
progress in eight others, leaving thirty-eight counties in which it had 
not been begun. 
The Mineral Production of Iowa in 1901 is reported by S. W. Beyer, 
in pages 37-61, its total being $12,204,160. Its several parts of chief 
importance were as follows: coal, $8,051,806; clay products, $2,774,200, 
stone, $781,756; gypsum, $562,500; lead and zinc, $16,500; and iron 
ore, $4,876. Each was considerably increased above the production 
for the year 1900, the aggregate increase being about $1,800,000. 
This volume contains reports on the geology of six counties, namely, 
Webster county, by Frank A. Wilder ; Henry county, by T. E. Savage ; 
Cherokee and Buena Vista counties, by Thomas H. Macbride ; Jefifer- 
son county, by J. A. Udden ; and Wapello county, by A. G. Leonard. 
Webster county is of exceptional economic interest on account of 
its extensive mines of coal and gypsum. An area of 60 to 70 square 
miles is occupied by the gypsum deposit, which varies in thickness 
from 10 to 25 feet, directly underlying the glacial drift. It is regarded 
as probably of Permian age, but possibly Triassic or Cretaceous. This 
chapter treats quite fully of the commercial uses of gypsum, giving 
details and statistics of its manufacture as plaster, and of its produc- 
tion in other parts of the United States, in Canada, and in European 
countries. It is followed by an important paper, in pages 193-223, on 
the Gypsum Industry in Germany. 
Each of the other counties described has many interesting features 
of stratigraphic geology and of the glacial drift series. Although Iowa 
has contributed much to the discovery of the complex history of the Ice 
age, much also yet remains to be ascertained, by further observations 
and discussion, concerning the mode of deposition, ensuing erosion, 
and age, of its successive drift formaations. w. u. 
A System of Glacier-Lakes in the Cleveland Hills. By Percy Fry 
Kendall, Lecturer on Geology at the Yorkshire College, Leeds, 
England. (Quart. Jour. Geol. Soc. ,vol. Iviii, pp. 471-571, with pis. 
xx-xxviii ; August, 1902.) 
The area here described is the northeast part of Yorkshire, adjoin- 
ing the coast of the North sea from Filey Brigg, near Flamborough 
head, northwesterly to the river Tees, and reaching back from the coast 
about thirty miles. The ice-sheet that overspread Scotland and Ire- 
land, the basin of the Irish sea, and northern England, flowed to the 
western and northern borders of this area; and on the east the con- 
fluent Scottish and Scandinavian ice-sheets pushed their margin across 
