MARYLAND GEOLOGICAL SURVEY 53

geology had come to take a leading position among the sciences. It
was only during the last decade of this period that anything like
modern methods of classification and of cartographic representation
of geological formations came to be generally adopted, yet during
these years much was done in the elucidation of the geology of Mary-
land.

The first observations upon the geology of Maryland during this
early period were made by Thomas Jefferson and published in his
" Notes on Virginia. " These notes, in which the author " speculates
on the geology of the state at Harper's Ferry, " were written in 1782
and a few copies published in French, the preface to the final publica-
tion of 1832 bearing the date of February, 1787.

In 1807 Joseph Scott published in Philadelphia " A Geographical
description of the states of Maryland and Delaware, " in which an
account is given of the natural features of the state, together with a
brief summary of Maryland's resources as then known.

About this time several papers relating to Maryland geology were
read before the American Philosophical Society of Philadelphia and
subsequently printed in its Transactions, among them being contribu-
tions by B. H. Latrobe, ¹ S. Godon, ² and Wm. Maclure. ² The latter
publication, entitled " Observations on the Geology of the United
States explanatory of a geological map, " contains broad generaliza-
tions regarding the geology of the country, in which we have the first
attempt at a correlation of American formations with those of Europe,
the Wernerian classification being adopted.

In 1810 Dr. H. H. Hayden presented a " Mineralogical and Geo-
logical Description of the Country Surrounding Baltimore, " in which
an area extending about nine miles from the city and including the
region of the Bare Hills, is considered.

In 1814 Robert Gilmor, Jr., published " A Descriptive Catalogue
of Minerals occurring in the vicinity of Baltimore, arranged accord-
ing to the distribution methodique of Hauy, "⁴ in which he enumer-
ates forty-three minerals found within a distance of 12 miles of the
city.

¹ Vol. vi, 1809, pp. 283-293. ³ Vol. vi, 1809, pp. 411-428.

² Vol. vi, 1809, pp. 319-323. ⁴ Bruce Min. Jour., vol. i, 1814, pp. 221-232.