82 HISTORICAL SKETCH

country by Professor P. K. Uhler of the Maryland Academy of
Sciences.

Further contributions were made by Professor Heilprin¹ upon the
Tertiary formations of Maryland during the years 1881 and 1882, in
which correlations are proposed for the Eocene and Miocene deposits
of the state.

An article entitled " Notes on the Cumberland or Potomac Coal
Basin, " by H. G. Jones, ¹ appeared during the latter year in the Pro-
ceedings of the American Philosophical Society, with a discussion by
J. P. Lesley. Professor I. C. White contributed an article upon the
same subject, which appeared in the same volume, entitled " A Rec-
tification of the Section made by Mr. Jones. "

Scharf's " History of Western Maryland, being a History of Fred-
erick, Montgomery, Carroll, Washington, Allegany and Garrett Coun-
ties from the earliest Period to the present Day, " contains an account
of the topography and geology by Professor Uhler.

The contributions of Professor F. D. Chester on the geology of
Delaware beginning in 1883 contain several references to the geo-
logical conditions of northeastern Maryland and should be consulted
in a study of that area.

Several articles were published by Mr. Persifor Frazer, Jr., upon
the geology of the northern portion of the Piedmont plateau during
this decade, in which the slate and copper rocks are especially con-
sidered.

In 1884 Professor Heilprin published an important volume, entitled
"Contributions to the Tertiary Geology and Paleontology of the
United States, " in which a systematic review is given of the Tertiary
deposits of the Middle Atlantic slope, and a classification of the Eocene
and Neocene deposits of Maryland is proposed.

Swank's " History of the Manufacture of Iron in all Ages, " pub-
lished in 1884, contains a special chapter entitled " Early Enter-
prises in Maryland, " in which the early furnaces of the state are de-

¹ Proc. Acad. Nat. Sci., Phila., vol. xxxiii, 1881, pp. 444-447. Ibid. vol.
xxxiv, 1882, pp. 150-186.
² Vol. xix, 1882, pp. 11-110.