Dring & Fage Timetable Sliding Rule

This yew wood and brass rule finds the number of weeks between two dates that were up to two years apart. The months of the year are listed along the right edge, from January to December, twice. The month names are adjacent to a continuous calendar for the 24 months, with seven days per row. A brass slide to the left of the calendar is numbered from 1 to 104 (for two years of weeks). A ring at the top for hanging the rule is marked: TIME TABLE. Dock companies used the rule to compute storage charges for goods shipped to or from British ports.

The right edge is marked: DRING & FAGE MAKERS TOOLEY S^T LONDON. The English firm established by John Dring and William Fage operated at various locations on Tooley Street from 1792 to 1882. For another timetable, or rent, rule by this maker, see inventory number 1954–305 at the Science Museum in South Kensington, London, http://www.sciencemuseum.org.uk/objects/mathematics/1954-305.aspx. The Science Museum owns several dozen other objects by this maker; see http://collectionsonline.nmsi.ac.uk/detail.php?type=related&kv=2628&t=people.

The back of the rule is stenciled: HWE. The Smithsonian acquired this object in 1962. No further information on the original owner is available.

Reference: Adler Planetarium, Webster Signature Database, http://historydb.adlerplanetarium.org/signatures/.

Currently not on view