64 HISTORICAL SKETCH

Creek Basin. " This pamphlet constituted the last report of the State
Geologist, although the office was not abolished until February, 1842.
The Topographical Engineer, who had not made any reports be-
tween the years 1837 and 1840, presented in 1841 a brief statement
regarding the " Trigonometrical survey for the new map of Mary-
land, " in which he urges the taking up of the plan of co-operation with
the U. S. Coast and Geodetic Survey which had been earlier arranged,
but which had been up to this time hindered because the national
bureau had been largely concerned with surveys to the north of Mary-
land. The general extension of these surveys to the borders of the
state made it possible for the first time to enter into active co-operation,
and the advantages of this are set forth in this report. The abolition
of the office of Engineer at the same time with that of Geologist in
February, 1842, ¹ put an end, however, to further operations.

INVESTIGATIONS MADE UNDER OTHER AUSPICES.

Considerable activity was manifested in the investigation of Mary-
land geology by others during the years that the official state survey
was in operation. Dr. H. H. Hayden, ² who had already contributed
much to local geology, prepared a description of the Bare Hills near
Baltimore in which various mineral localities are described and indi-
cated upon the map which accompanied this article.

During the same year Messrs. Isaac Lea and S. G. Morton³ discussed
the Tertiary and Cretaceous deposits, the latter tracing the extension
of the greensand beds from New Jersey across Delaware into Mary-
land.

An important article by W. E. A. Aikin, entitled " Some notices of
the Geology of the Country between Baltimore and the Ohio River,
with a section illustrating the superposition of the rocks, " was pub-
lished in the American Journal of Science in 1834. ⁴ This article
contained the most complete description of the geology of central and
western Maryland that had been published up to that time.

¹ Laws of Maryland, 1841, Chapter 153, passed Feb. 24, 1842.

² Amer. Jour. Sci., vol. xxiv, 1833, pp. 349-360, map.

³ Amer. Jour. Sci., vol. xxiii, 1833, pp. 2SS-294; vol. xxiv, 1833, pp. 128-132.

⁴ Vol. xxvi, pp. 219-232, plate.

[The next page is an image: The Potomac River Valley at Williamsport, on the Western Maryland Railroad]