292 BIBLIOGRAPHY AND CARTOGRAPHY

MERRILL, GEO. P. (ISTotes on the Building stones of Washington,
D. C.)

Tenth Census, vol. x, Washington, 1884, p. 357.

———— Preliminary note on the Crystalline schists of the District
of Columbia.

Proc. U. S. Nat. Mus., vol. vi, 1884, pp. 159-161.
(Abst.) Science, vol. ii, 1883, pp. 829-830.

The prevailing Indigenous rock of the District is an extremely variable hornblende,
chlorite or micaceous schist.

PHILLIPS, HENRY, JR. Early Proceedings of the American Philo-
sophical Society (1744-1838).

Proc. Amer. Phil. Soc., vol. xxii (2), 1884.
Contains references to early papers and early discoveries.

RAU, CHAS. Prehistoric Fishing in Europe and North America.

Smithsonian Contrib. Knowledge, vol. xxv, 1884, 360 pp.

Pages 235-239 are devoted to a discussion of the shell heaps of Maryland (based on
notes of Dr. E. R. Raynolds and J. D. McGulre which have proved liable to confusion
with Tertiary deposits. (See Conrad and Vanuxem.)

ROGERS, WILLIAM BARTON. A reprint of Annual Reports and other
papers, on the Geology of the Virginias, sm. 8vo. Appleton, 1884.

Contains pocket maps and sections along the Potomac.

SMOCK, J. C. Geologico-geographical Distribution of the Iron Ores
of the Eastern United States.

Eng. and Min. Jour., vol. xxxvii, New York, 1884, pp. 217-218, 230-232.

Trans. Inst. Min. Eng., vol. xii. 1884, pp. 130-144.

Reference to occurrence of iron ores in Maryland, Including the Allegany county
occurrence of siderite. the Washington county ores which are of Silurian age, and mag-
netite at Deer Creek, Harford county.

SPENCER, F. W., and KELLY, THOS. C. Statistics of Building Stones.

Tenth Census, vol. x, Washington, 1884, pp. 45-105 of Report on Building
Stones.

Maryland references, pp. 46, 48, 50, 74-75.

SWANK, JAMES M. History of the Manufacture of Iron in all Ages.
Phila. 1884.

Special chapter entitled " Early enterprises in Maryland," pp. 182-107. The first
works were at North East and Principio. See also pp. 202-203.

WALLING, H. F. Topographical Indications of a Fault near Harp-
er's Ferry. (Abst.)

Bull. Phil. Soc., Washington, vol. vi, 1884, pp. 30-32.

Mentions the discontinuous extension of the Blue Ridge at Harper's Ferry in sup-
port of increased corrugation and steepness of dip eastward with reversed folding. The
downthrow to the west.