ILLUSTRATIONS. 
Page. 
Plate I. Areas underlain by Lower Cretaceous water horizons in New Jersey . 40 
II. Areas underlain by Upper Cretaceous and Chesapeake water hori- 
zons in New Jersey 44 
III. Sections across southern New Jersey 48 
IV. Columnar section of artesian wells at Atlantic City, N. J 52 
V. The Coastal Plain region of Maryland and Delaware, showing rela- 
tions of underground waters 118 
VI. Sections, Maryland and Delaware 122 
VII. Map of Baltimore regiou, illustrating features of underground 
waters 136 
VIII. Sections, Baltimore region 142 
IX. Potomac gravels on crystalline rocks, North Charles street, Balti- 
more ; looking north 146 
X. Severn clays on Magothy sands, shore of Chesapeake Bay, 1 mile 
north of Grove Point, Cecil County, Md. ; looking east 152 
XI. Potomac gravelly sands on crystalline rocks, Quarry road, near 
Zoological Park, Washington, D, C. ; looking north 154 
XII. Arkosic sands of Potomac formation, Sixteenth street, just north of 
Florida avenue, Washington, D. C. ; looking east 156 
XIII. Map of a portion of the District of Columbia, illustrating features 
of underground waters 158 
XIV. Sections, District of Columbia 160 
XV. Map of eastern Virginia, showing distribution of underground 
waters 162 
XVI. Sections, eastern Virginia 174 
XVII. Portions of South Carolina and Georgia, showing location of deep 
wells 208 
XVIII. Sections, eastern South Carolina 212 
XIX. Columnar section of well at Charleston, S. C 216 
Fig. 1. Section across the Atlantic Coastal Plain from west to east 18 
2. Ideal sections illustrating certain general conditions affecting under- 
ground waters 20 
3. Ideal sections illustrating certain special conditions affecting well 
prospects 21 
4. Ideal section illustrating water-bearing beds in channels 21 
5. Ideal section illustrating the occurrence of local clay strata in gravels 
and sands 22 
6. Ideal section illustrating water-bearing beds intercepted by a valley. . 22 
7. Cross section of the western end of Long Island 23 
8. Cross section of eastern North Carolina 194 
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