Gauging Rule (2)
 Front
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 Front Left |
 Front Right |
 Back Left |
 Back Right |
 Front Edge Left |
 Front Edge Right |
 Top Edge Left |
 Top Edge Right |
 Side View (Note that the slides have slots and the body has tongs. Also note that the tongs are made from separate piece of wood.) |
 Two Slides Butted Against Each Other |
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This rule is "Gauging Rule" which was used in England for taxation purposes between 18th and 19th Centuries. The tax collector measured outside dimensions of a cask containing spirits and calculated the volume by using the gauging rule. This particular specimen does not have the maker's name on it. But it has a whopping 27 scales, including 5 smaller ones. It has scales on both edges of the body as well. It has two slides, each with a pair of single cycle logarithmic scale on top and bottom (and front & back as well.) Two cursors are needed to access many scales on the stator in absence of a cursor. Another neat feature of this rule is that you can pull out one slide and insert it on the other slot, thereby joining two slides together, and you get a two cycle logarithmic scale. You will never get "scale over run" on this rule.Click here for scale details. |