1 Very few of the topographic and hydrographic field sheets are published, but the data which they contain are combined so as to form Charts on different scales. These Charts can be obtained at the prices given by addressing The State Geologist, Baltimore, Md., or The Superintendent U. S. Coast and Geodetic Survey, Washington, D. C., or from local agents. The position of the Charts is shown upon the accompanying map. This Chart includes the area covered by all of the others. PART III OUTLINE OF PRESENT KNOWLEDGE OF THE PHYSICAL FEATURES OF MARYLAND EMBRACING AN ACCOUNT OF THE PHYSIOGRAPHY, GEOLOGY AND MINERAL BY WM. BULLOCK CLARK OUTLINE OF PRESENT KNOWLEDGE OF THE PHYSICAL FEATURES OF MARYLAND, EMBRACING AN ACCOUNT OF THE PHYSIOGRAPHY, GEOLOGY AND MINERAL The present account of the physical features and natural resources of Maryland should be regarded solely in the light of a preliminary statement. While certain parts of the state have in later years received detailed investigation, there are many portions which are as yet but imperfectly known and some which have never been examined at all. Still, on the basis of this somewhat unequal knowledge, it seems desirable to prepare a brief general account at the present time, a more detailed treatment being accorded to each subject as investigation proceeds. In the succeeding chapters the chief facts concerning the physical features of Maryland will be considered, but in order that this information may be placed in proper setting, a few preliminary remarks regarding the geographical position and political divisions of the state are necessary. Maryland is situated between the parallels of 37° 53' and 39° 44′ north latitude, and the meridians of 75° 04′ and 79° 33′+ west longitude, the exact western boundary being yet undetermined. Its boundaries are: Mason and Dixon's line, separating it from Pennsylvania on the north; the state of Delaware and the Atlantic Ocean on the east; on the south Virginia and West Virginia, separated by a line drawn from the ocean to the western bank of the Potomac river, and thence following the western bank of that river to its source; and on the west, West Virginia, separated by a line drawn due north from this source to Mason and Dixon's line. The gross area of the |