80 HISTORICAL SKETCH

timore"¹ and " Amphibole-Anthophyllite from Mount Washington,
Baltimore County. "²

The work which Dr. Williams had been conducting upon the ancient
eruptive rocks to the north and west of Baltimore ever after his arrival
in Maryland found expression in a memoir entitled " The Gabbros and
associated Hornblende Rocks occurring in the neighborhood of Balti-
more, Maryland, "³ that was published by the United States Geological
Survey in 1886. A short article " On a Remarkable Crystal of
Pyrite from Baltimore County, Maryland, " ⁴ appeared in the Univer-
sity publications the same year.

The growth of the Geological Department and the wider insight
which was acquired regarding the complicated geological history of
the Piedmont belt led to the preparation of a systematic scheme for
the geological mapping of the region about Baltimore. An account
of this is found in an article " On a Plan proposed for Future Work
upon the Geological Map of the Baltimore Region. " ⁵ A small pam-
phlet was also brought out by Dr. Williams about this time upon
" Notes of the Minerals occurring in the Neighborhood of Baltimore. "⁶

In the autumn of 1887 Dr. William B. Clark became associated
with the Johns Hopkins University as instructor of stratigraphic
geology and paleontology, and at once took up a study of the geo-
logical formations represented in the eastern and southern portions of
the state, and an article " On Three Geological Excursions made
during the months of October and November, 1887, into the Southern
Counties of Maryland " ⁷ was published in the University Circulars in
1888.

In conformity with the plan outlined by Professor Williams and
above described, Mr. W. H. Hobbs, a student of the University, pre-
pared an article " On the Rocks occurring in the Neighborhood of

¹ Johns Hopkins Univ. Circ. No. 38, vol. iv, pp. 65-6C.

² Amer. Nat., vol. xix, pp. 884-886.

³ Bull. U. S. Geol. Surv. No. 28, 78 pp., 4 pls.

⁴ Johns Hopkins Univ. Circ. No. 53, vol. vi, p. 30.

⁵ Johns Hopkins Univ. Circ. No. 59, 1887, pp. 122-123.

⁶ Baltimore, 1887, 8vo, 18 pp.

⁷ Johns Hopkins Univ. Circ. No. 63, vol. vii, pp. 65-67.