MARYLAND GEOLOGICAL SURVEY 125

sity, has been studied for Baltimore and a number of surrounding
stations available for Maryland. Appendix No. 1, Report for 1895,
covers the whole period from the discovery of the country to the pres-
ent time. The latest isogonic chart for the United States is given
in Appendix No. 1, Report for 1896, and is for the epoch January,
1900. Isoclinic and isodynamic charts, the latter for the horizontal
component of the magnetic force and for the total intensity, have
likewise been constructed for the same advanced epoch.

INVESTIGATION OF OYSTER-BEDS. —The investigations were conducted
by Francis Wilson, U. S. N., in Manokin river, Nanticoke river,
Wicomico river, Big Annemessex river, Fishing Bay, Kedge Strait,
Hooper Strait and Holland Strait. The object of this work was to
determine the extent of the oyster-beds and to study the habits of the
oyster, as will be seen in Appendix No. 11, Report for 1881. The
examination was conducted between August 7, 1878_; and October 15,
1878, in the Coast Survey schooner " Palinurus. "

HYDROGRAPHY. —The work was executed by both civilians and
naval officers, and includes the ocean shore as well as Chesapeake Bay
and the rivers tributary to it. The area covered by this hydrography
is about 2600 square miles. The number of miles of shore line is
approximately 2800.

In connection with the hydrography, tidal observations were made
at 113 stations, varying from two days to several months in duration,
depending upon the needs of the hydrographic party.

TOPOGRAPHICAL SHEETS WITHIN BOUNDARIES OF THE STATE OF

MARYLAND.

ON FILE IN THE ARCHIVES OF THE U. S. COAST AND GEODETIC SURVEY, GEOGRAPH-
ICALLY ARRANGED, GIVING NUMBER OF SHEET, LOCALITY OF SURVEY, SCALE,
TOPOGRAPHER AND DATE.

			Atlantic Coast	,
	Register
	No.	Locality.	Scale.	Topographer.	Date.
	299	From Salt Pond Beach Signal
		to Dromedary Signal......	1-20000	G. D. Wise,	1850
	263	From Beach House to South Birch....................	1-20060	G. D. Wise, L. A. Sengteller,	1849 1877
	264	From head of Assateague Bay
		to Popes Island Beach.....	1-20000	G. D. Wise,	1850