Computer History Museum

Coggeshall timber measurement slide rule

A folding carpenter's measuring rule with a brass slide set into one arm - that arm and slide are a logarithmic slide rule. This is one member of the family of rules originally described by Henry Coggeshall in the 1677 pamphlet entitled Timber Measure by a Line of more Ease, Dispatch and Exactness than any other way now in use, by a Double Scale. . . ., London. This version takes the form of a 2-foot long jointed (hinged) rule with a slide set into one of the two 1-foot long legs. In addition to the slide-rule scales, there are other scales, including a ruler, on both sides of the two legs. This family of rules was particularly adapted to calculations required by timber merchants, builders, and others who dealt with length, area, and volume measurements. Coggeshall rules remained in use for approximately 200 years.

Coggeshall timber measurement slide rule - Image 1
Coggeshall timber measurement slide rule - Image 2

Item Details

Date
ca. 1800 (Made)
Type
Physical Object
Catalogue number
B170.81
Category
Slide Rule
Credit line
Courtesy of Gordon and Gwen Bell
Weight
1 (lb)
Acquisition number
X6288.2012
Subject
Analog, Hand Calculation