[A Contraction of Do.] No. 89 B. / Copied from a Plan of Mr Rittenhouse's by Robt Erskine F.R.S. 1779 ; by Robert Erskine F.R.S. Geogr. A. U.S. and Assistants.

Foxed, soiled, frayed. Sheathed in mylar. In ink on verso: "No. 89 B." In pencil on recto: "No 89 B". Military topographic map. Covers the counties of Chester, Montgomery and Delaware, Pennsylvania. Shows roads running through Norristown and Philadelphia. Also shows buildings and owners' names, landforms and streams. No title on recto or verso; title proper supplied by cataloger. Title number from map verso. First statement of responsibility from map recto. Full index title, secondary statement of responsibility, date, series title and series numbering by Erskine, but on separate index sheet filed at head of series. Oriented with north to upper left of sheet. Pen-and-ink, pencil on laid paper. Size includes 3 x 12 cm. tab joined to main sheet at lower left corner. Shows relief by hachures. Watermarks: "J WHATMAN" accompanied by "GR" beneath sheield; similar to Gravell and Miller foreign watermarks nos. 301 and 751.