178 
The American Geologist. 
March, 1896 
to which it belongs, repeated nearly the same in other folios of that re¬ 
gion. The special contour and the development of the geologic forma¬ 
tions in the limited district of the folio are described in much detail; 
and the economic resources, especially for mining and quarrying, the 
varieties of soil, and their adaptation for agriculture, are very fully 
noted. 
The first map sheet in each folio shows the topography, with contour 
lines, printed in brown, having vertical intervals of 100 feet, excepting 
the Livingston and Lassen Peak folios, in which the contours are 200 
feet apart, and the Fredericksburg folio, lying wholly on the coastal 
plain of Virginia and Maryland, which has contours for each 50 feet. 
The drainage, as rivers and smaller streams, lakes, marshes, and the 
sea, are printed in blue; and “the works of man, called culture , as roads, 
railroads, boundaries, villages and cities,” and all the nomenclature, are 
in black. 
A second sheet adds to the preceding the color-printing by which the 
areal geology is displayed. 
A third sheet, in every folio excepting the Fredericksburg, is a some¬ 
what modified geologic map, giving special prominence to the economic 
geology, as formations bearing ores, coal, or building or ornamental 
stone, and the locations of mines and quarries. 
A fourth sheet, in all excepting the Fredericksburg and Lassen Peak 
folios, is geologically colored but is crossed by narrow blank belts in 
which the sections of the rock structure are displayed, drawn on the 
same scale for both length and hight. 
Finally in about half of the folios, a sheet is devoted to columnar sec¬ 
tions, noting the stratigraphic order and the approximate thickness of 
each rock formation, with their geologic classification and lithologic 
characters, and the prevailing topographic condition of their areas. 
Arranged in geographic order from east to west, and secondarily from 
north to south, the folios thus far printed and distributed are as fol¬ 
io vvs: 
Fredericksburg folio (13), in Virginia and Maryland, by W J McGee 
and N. H. Darton. 
Harper’s Ferry folio (10), in Virginia, West Virginia, and Maryland, 
by Arthur Keith. 
Staunton folio (14), in Virginia and West Virginia, by N. H. Darton. 
Estillville folio (12), in Virginia, Kentucky, and Tennessee, by Marius 
R. Campbell. 
Knoxville folio (16), in Tennessee and North Carolina, by Arthur 
Keith. 
Kingston folio (4), in Tennessee, by Charles Willard Hayes. 
Cleveland folio (20), in Tennessee, also by C. W. Hayes. 
Chattanooga folio (6), in Tennessee, by C. W. Hayes. 
Sewanee folio (8), in Tennessee, by C. W. Hayes. 
Ringgold folio (2), in Georgia and Tennessee, by C. W. Hayes. 
Stevenson folio (19), in Alabama. Georgia, and Tennessee, by C. W. 
Hayes. 
