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.
- This six-inch wooden ruler is beveled and coated with white plastic along both long edges. One side is divided to 1/50" and numbered in both directions from 0 to 6. The number "50" is printed below the three-inch mark, and the center of the rule is marked: ALTENEDER. The other side is divided to 1/32" and numbered in both directions from 0 to 6. The number "32" is printed below the three-inch mark, and the wooden part of the rule is marked: B. K. ELLIOTT Co. PITTSBURGH – CLEVELAND. It is also marked: R. S. C. It is also marked: U.S. ST'D.
- Theodore Alteneder began making drawing instruments in Philadelphia in 1850, and the firm remains in existence as a manufacturer of photoengraving equipment. Byron Kenneth Elliott (b. 1870) opened a store in Pittsburgh in 1897 that sold drawing, surveying, and optical equipment. The shop closed in 1980. The donor's father, Robert S. Condon, used this instrument.
- The date for this object is uncertain. Theo. Alteneder & Sons made a 6" opposite bevel scale with white edges and these divisions as model 2232 from 1940 (when it cost $1.35) to at least 1958 (when it cost $3.25). However, according to catalog illustrations, the company mark during this period had the firm's full name around a circle, while this object has only "Alteneder" in a straight line. The scale does not appear in the 3rd, 5th, or 1948 7th editions of B. K. Elliott catalogs.
- References: "Byron Kenneth Elliott," in History of Pittsburgh and Environs (New York and Chicago: American Historical Society, 1922), 35–36; Alteneder Drawing Instruments (Philadelphia, 1940), 26; Alteneder Drawing Instruments (Philadelphia, 1958), 26; Catalogue and Price List of B. K. Elliott Co., 3rd ed. (Pittsburgh, n.d.), 134, 140; Catalogue and Price List of B. K. Elliott Co., 5th ed. (Pittsburgh, n.d.), 135; Catalogue and Price List of B. K. Elliott Co., 7th ed. (Pittsburgh, 1948).
- Currently not on view
- date made
- 20th century
- B. K. Elliott Co.
- Theo Alteneder & Sons
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History, Kenneth E. Behring Center