Scale RulesCalculating Rules
In addition to length measurements, scale rules could be marked with aids for calculation. Perhaps the most notable rule of this type was Gunter's scale, which was similar to a sector or a slide rule. Gunter's scales are named after Edmund Gunter, a 17th-century English mathematical practitioner who figured out how to put a table of logarithms on a rule so that logarithmic calculations could be made with the aid of dividers. These instruments were especially handy for mathematicians and navigators.
The mathematics collections contain several other objects, ranging from the 18th to the 20th centuries, that were used to simplify computations for tasks including designing sundials, keeping track of calendar dates, and plotting data for aeronautical engineering. A few of these rules were designed specifically for positioning artillery.
"Scale Rules - Calculating Rules" showing 1 items.
- 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 ST 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
- date made
- Dring & Fage
- ID Number
- catalog number
- accession number
- Data Source
- National Museum of American History, Kenneth E. Behring Center