- This two-sided rule made by Uarco Incorporated has its original manila paper sleeve. The front of the rule has a silver background with black markings and the back has a black background with silver marking. The front is marked with two scales. Along the top edge, the 16 inch length is divided into 16th of an inch spaces. The bottom edge is marked with a 160 space scale divided into tenths of an inch. The back also has two scales, a 50 centimeter metric scale divided into millimeters along the top edge and a 16 inch scale divided into 6ths and 12ths along the bottom edge.
- The rule was used by museum staff to mark out lines of typed data and to confirm character and line spacing on optical character recognition (OCR) typed pages.
- In 1975 the museum began automating its accession records. Information from these records was typed on an IBM Selectric typewriter using special paper designed for OCR scanning and an OCR-A type font element. Each page started with a formatted unique number and each line of data started with a 5-digit code that identified the type of data and the line number associated with it. (e.g. 11001 identified the data as the donor name on line 1; 11002 would identify a second donor name.)
- If there was a line of data on an OCR typed page that was not to be scanned, a black pen was used to draw a horizontal line through the center of the 5-digit line code. The OCR scanner would ignore any data line if it detected a 5-space black line. This rule was used to draw an accurate line.
- To ensure accurate scans, the data had to be precisely spaced both horizontally and vertically. This rule was used to check the number of spaces between the line code and the start of the data, the space between the OCR characters, as well as the vertical distance between data lines. Data entry workers could reinsert typed pages into the typewriter to correct typographical errors (using the Selectric’s correction tape) or to add data lines at the bottom of a page. The rule was used to confirm the horizontal and vertical spacing accuracy of these edits.
- Once all editing was completed, the OCR pages were scanned and copied to 9-track magnetic reel tape by a third party vendor, and then processed on the Smithsonian’s Honeywell mainframe computer.
- Currently not on view
- Object Name
- Uarco Incorporated
- Physical Description
- metal (overall material)
- overall: 41.3 cm x 3 cm; 16 1/4 in x 1 3/16 in
- ID Number
- accession number
- catalog number
- See more items in
- Medicine and Science: Mathematics
- Computers & Business Machines
- Science & Mathematics
- Scale Rules
- Data Source
- National Museum of American History
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