The Naghel exercise book (162 pages), titled Cahier de navigation, is a mathematical workbook on the art of navigation. The volume once belonged to Captain Francis Naghel, and includes documents and correspondence related to two of his descendants.
The navigational instructions comprise 143 pages of the volume. Individual sections often pertain to a rule with related examples and mathematical problems that often require fairly complex solutions. The volume covers specific topics such as plotting navigational courses, determining one's position, and using nautical instruments to establish direction and location. Many of the examples show practical applications and are illustrated by geometric figures or drawings of related nautical tools, and some also contain relevant charts.
- Compass (p. 47)
- An oblique sphere showing signs of the zodiac, with a picture of a small rowboat in the lower left corner (p. 73)
- Navigational problem illustrated by a half-globe and two sailing ships (p. 127)
The final 19 pages consist of pasted-in documents pertaining to Naghel and two of his descendants. These are a document certifying Naghel's American citizenship, dated June 12, 1806; a letter to Naghel's wife from her brother, Emanuel West (October 21, 1825); and documents that relate to Edward Q. Naghel, a dentist from New Albany, Indiana, and to Charles E. Naghel, a Marine commended for his work with the 1930 census in Alaska. The volume is bound in vellum.