C-Thru Pocket Slide Rule


This inexpensive five-inch white plastic rule has A and D scales on the front of the base; B, CI, and C scales on the front of the slide; and S, L, and T scales on the back of the base. The indicator is clear plastic. Underneath the slide is a table of equivalents and settings. The front of the slide also has a scale of six inches, divided to sixteenths of an inch, and a scale of 15.3 centimeters, divided to millimeters. The back of the slide has a table of decimal equivalents from 1/64 to 63/64. A brown imitation leather sheath is marked: POCKET SLIDE RULE MADE IN U.S.A. No. 27. For instructions, see 1988.0807.06. The postal code on the instructions indicates a date between 1943 and 1963. According to this sheet, the C-Thru Ruler Company of Hartford, Conn., made this rule. This firm, established in 1939 by teacher Jennie Zachs and acquired by Acme United Corporation in 2012, continues to make transparent drafting tools and drawing instruments.

References: Brian Dowling, "Acme United Acquires Bloomfield's C-Thru Ruler," Hartford Courant, June 11, 2012; "About Us," C-Thru Ruler Company, http://www.cthruruler.com/.

Date Made: 1943-1963

Maker: C-Thru Ruler Company

Location: Currently not on view

Place Made: United States: Connecticut, Hartford

Subject: MathematicsRule, CalculatingEducation


See more items in: Medicine and Science: Mathematics, Science & Mathematics, Slide Rules


Exhibition Location:

Credit Line: Gift of George A. Norton

Data Source: National Museum of American History

Id Number: 1988.0807.02Accession Number: 1988.0807Catalog Number: 1988.0807.02

Object Name: slide rule

Physical Description: plastic (overall material)Measurements: overall: .4 cm x 17 cm x 4.4 cm; 5/32 in x 6 11/16 in x 1 23/32 in

Guid: http://n2t.net/ark:/65665/ng49ca746aa-9c96-704b-e053-15f76fa0b4fa

Record Id: nmah_1215009

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