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.
- Frank G. Hunt of Buffalo, N.Y., designed this flexible steel rule for drawing straight lines on curved surfaces, such as those of ledger books. The rule has no scales, but it has a small round metal handle in the middle of the front. Nine rectangular clips on the back hold several layers of paper covered by a metal rectangle. The middle clip is marked: EXP. ACC'T. F. G. HUNT (/) PAT'D. FEB.25.02 (/) BUFFALO, N.Y. Hunt distributed the rule via the Hunt Ruler Company in Buffalo at least as late as 1920. By 1922, he had passed away but the firm was expanding.
- References: Frank G. Hunt, "Flexible Ruler" (U.S. Patent 694,061 issued February 25, 1902); "Buyers' Reference Bureau: Rulers: Metal or Steel," The American Stationer and Office Outfitter 86, no. 18 (May 8, 1920): 102; "Hunt Ruler Company Expanding," Office Appliances 36 (July 1922): 49; Buffalo Historical Society, "Buffalonians More or Less Noted, Who Died in 1922," in Reports of the President and Secretary (Buffalo, 1923), 46.
- Currently not on view
- date made
- 1902–ca 1922
- inventor; patentee
- Hunt, Frank G.
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History, Kenneth E. Behring Center