Scale RulesRules for Drafting
To create technical drawings such as those presented by the traveling exhibition, Doodles, Drafts, and Designs, draftsmen needed drawing instruments with specialized scales. Most often, their goal was to represent a real-life place or object at a reduced proportion. Thus, drafting rules like those shown on this page were typically marked for making drawings at scales such as 1/8-inch to 1 foot. Sometimes, instead of marking the increments throughout a scale, only the first and last segments of a scale were subdivided to the desired proportion. These were called open divided or architect's scales.
Rules for drafting sometimes had plotting scales. These were divided into equal increments of a useful length, such as 1/2-inch, that could be directly transferred to a drawing such as a surveying map. At both ends, plotting scales typically had diagonal scales. These allowed users to reasonably accurately estimate the decimal division between two markings on a scale. Instruments in this category also may have a line of chords. This projected the distance between the end of a quarter-circle arc and each of the degrees along the arc onto a straight line. Finally, the scales for measuring lengths on rules for drafting were often divided into multiples of 1/10-inch, called chain scales, which were advantageous for activities such as construction or machine work.
"Scale Rules - Rules for Drafting" showing 1 items.
- On one side this silver-colored metal rule has a 16-cm plotting scale with diagonal scales at each end (graduated to 5 mm and to 1 mm). The plotting scale is divided to centimeters. It is numbered along one edge by hundreds from 0 to 300 (representing a scale drawing at a proportion of 1 cm to 2,000 meters) and along the other edge by twenties from 10 to 150 (representing a scale of 1:1,000). The right end is marked: GEBR. WICHMANN BERLIN.
- The other side has another 16-cm plotting scale with diagonal scales at each end (graduated to 4 mm and to 2 mm). The plotting scale is divided to two centimeters. It is numbered along one edge by hundreds from 0 to 400 (representing a scale of 1:2,500) and along the other edge by hundreds from 0 to 800 (representing a scale of 1:5,000). A cardboard case is covered with black leather and lined with dark blue velvet. The case is marked: GEBR. WICHMANN BERLIN.
- Gebr. Wichmann (Wichmann Brothers) was founded in Berlin in 1873 and continues to distribute office and technology products. Ernst Emil Herzfeld (1879–1948) is believed to have used this scale on archaeological expeditions and excavations in the Middle East between 1903 and 1936.
- References: Gebr. Wichmann, "Wir über uns," http://www.wichmann.de/fip_Ueber_uns-30.html; accession file.
- Currently not on view
- date made
- early 20th century
- Gebr. Wichmann
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History, Kenneth E. Behring Center