National slide rule
Date: circa 1960
Inventory Number: 2004-1-0020
Classification: Slide Rule
Dimensions:4.6 × 31.6 × 6 cm (1 13/16 × 12 7/16 × 2 3/8 in.)
DescriptionRectangular white plastic slide rule with three slides. The top and bottom slides are fixed to horseshoe-shaped black end caps; the center slide moves to left and right. A clear plastic runner with vertical indicating line also moves to left and right.
Nine scales are printed on the face of the rule. Near the top of the top, fixed slide is a "K" scale composed of three logarithmic scales (values 1 to 10) placed side by side. Below this is an "S" scale with values ranging from 35' to 90°.
Printed along the bottom of the top slide is an "A" scale composed of two logarithmic scales (values 1 to 10) placed side by side. An identical "B" scale is printed along the top edge of the center, moveable slide.
Printed along the center of the center slide is an inverted logarithmic scale "CI", with values descending from 10 to 1.
Along the bottom edge of the center slide is a logarithmic "C" scale carrying values from 1 to 10. Printed along the top edge of the bottom, fixed slide is a logarithmic "D" scale identical to the "C" scale above.
Printed along the center of the bottom slide is a "T" scale with values ranging from 5.5 to 45. Near the bottom of the same slide is an "L" scale carrying values from 0 to 10.
The back of the slide rule is blank, except for a mark (center slide) left by a strip of tape.
Signedface, center slide, center left: DIETZGEN / NO. 1767;
face, center slide, center right: DIETZGEN / NO. 1767
Inscribedface, top slide, center right: National
face, bottom slide, center right: MADE / IN / U. S. A.
FunctionFor solving mathematics problems, including multiplication, division, squares, square roots, cubes, cube roots, and trigonometric problems.