Mathematical Treasure: Rosewood Slide Rule and Gauging Rods

Once the function concept of a slide rule was understood, many slide rules were constructed for specific purposes and sets of calculations. Here is an example of an 18th-century slide rule made of rosewood and used by British excise (tax) officers in their gauging duties. They would visit pubs and inns and measure the amounts of alcoholic beverages on the premises and compute the excise taxes due. This particular rule has an accompanying set of adjustable gauging rods included. The rods can be adjusted to measure a depth up to five feet.

Source: Oughtred Society, Archive of Collections, Tom Wyman Collection. Tom Wyman (1927-2014) was the first president of the Oughtred Society. Wyman amassed an extensive collection of early slide rules and books related to them. The images above are, respectively, images #1, #2, #5, and #6 in Item 20 in the Wyman Collection.

Index to Mathematical Treasures

Index of Mathematical Objects