Foxed, soiled, stained and creased. Mounted on cloth and cropped. In pencil on recto: "No 89". Includes index to 66 numbered features. Military topographic map. Covers the counties of Berks, Chester, Montgomery and Philadelphia, Pennsylvania, between Reading and Philadelphia. Shows river features and depths by soundings. Does not show landward features. Pen-and-ink, pencil on laid paper. Title proper and first statement of responsibility from map recto. Title number supplied by cataloger. Erskine’s title, his statement of responsibility, date, series title and series numbering from separate index sheet filed at head of series. Watermark on all sheets: "J WHATMAN" accompanied by "GR" under shield, similar to Gravell and Miller foreign watermarks nos. 301 and 751.