Images(2)

Circumference Rule

Date1840-1880

OriginAmerica or England

MediumIron / steel

DimensionsOL: 36" OW: 1 3/8"

Credit LineGift of Judith and William McMillen

Object number2012-35

DescriptionCircumference rule, hand stamped.
Label TextWhile at first glance this rule may appear to be a standard "yard stick" made of steel, it is actually a specialized tool. Completely hand-stamped with individual punches, the top is graduated in inches and the bottom in centimeters.

However, it is the back side which makes the piece trade-specific. Struck into the rule are a number charts giving dimensions for both dry and liquid measures, for both tapered and straight sided vessels.

One of the rudiments of tinsmithing is knowing how to lay out a proper pattern. As a rule, a measure must "measure" out an exact quantity of material, the dimensions specified by this rule were indispensible for the trade. Thus equipped, a sheet metal worker could layout patterns for measures as small as a quart or as large as a 200 gallon container.