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.
- These eight white plastic rules have scales dividing 10 centimeters into proportions of 1:75, 1:50, 1:40, 1:33-1/3, 1:30, 1:25, 1:15, and 1:10. They are fastened together inside a brown leather sleeve marked: BLUE (/) WHITE. The words form a logo with a triangle and T-square. The 1:75 rule is marked: ARISTO (/) Nr. 1324. Inside the sleeve is a price tag marked: BLUE & WHITE (/) ESCALA (/) ARISTO (/) NO. 1324 (/) $30.00.
- In 1948 the German slide rule company, Dennert & Pape, was renamed Aristo, after the brand of plastic slide rules the firm was then manufacturing. Aristo stopped manufacturing mathematical instruments in 1978 and turned to computer-aided design. Model 1324 is shown in a 1955 catalog, alongside other rulers and architect's scales. The donor, Sebastian J. Tralongo (1928–2007), served in the U.S. Navy during World War II and then worked for the Vitro Corporation in Rockville, Md., for 35 years. He patented a device for signaling from deeply submerged submarines.
- References: International Slide Rule Museum, "Aristo," http://sliderulemuseum.com/Aristo.htm; Walter Shawlee II, Ted Hume, and Paul Ross, "Aristo Slide Rule Archive," Sphere Research Corporation, http://www.sphere.bc.ca/test/aristo.html; Aristo Slide Rules & Drafting Instruments (Germany, ), 36; "Tralongo, Sebastian James 'Subby'," Hartford Courant, May 26, 2007; Sebastian J. Tralongo, "Submarine Signal Device" (U.S. Patent 2,989,024 issued June 20, 1961); "Vitro Corp. – Company Profile," http://www.referenceforbusiness.com/history2/25/Vitro-Corp.html.
- Currently not on view
- date made
- Dennert and Pape
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History, Kenneth E. Behring Center