Geology and Mineralogy. 241 
Low Moor iron, on the other hand, which has been subjected to 
the same vicissitudes as the bronze bar before mentioned, has 
long in the possession of the U. 8. Coast’ Survey, was compar 
11. Magnetic Declination in Missouri.—A chart has been 
KE, Ni 
ter of the State there is a correspondingly sharp bend to the east- 
ward. (See this Journal, xix, 234, 1880). 
II. GkoLogy AND MINERALOGY. 
|. Pennsylvania Geological Survey: The Geology of McKean 
County, and its connection with that of Cameron, Elk and 
vrest ; by Cuartes A. AsnpurNER. Report of Progress, No. 
R. 372 pp. 8vo. With 33 plates and 2 maps. Harrisburg: 
1880.—McKean, one of the northern counties of Western Penn- 
ylvania, adjoins Cattaraugus County and a part of Allegany 
ounty of N 
art IT, he gives the detailed geology of the county, under 
Which are ettngh out many se Wie illustrating the Bradford 
oil district. 
e oy a is part of the elevated plateau that stretches west 
t - . 
Table land to the south, the northwestern flank of the mountain 
rnge. The surface has “a mean height of nearly 2000 feet above 
the ocean,” but many elevations over it reach to 2200 feet, and 
One to 2500. : 
The rocks at the outcrops—which are not numerous or good— 
ate SO nearly horizontal that what there are of anticlinals and 
Synclinals consist mostly of slightly curving “domes and dim- 
