Another from my trip to my favorite antiquarian bookseller in Maine this week, this one a geometry notebook from 1838, which sold me on the first page alone--which I might be tempted to extract and frame, though the notebook is thin enough it could just be folded open to show that one and kept in tact. Something so satisfying to my eye about these sorts of geometric diagrams--if only everything could be so ordered and rational! 

8 1/2" x 6 1/2". Brown paper covers plus 6 pages filled front and back. All in very good condition, with ink strong and bold--better than photos convey.