Keuffel & Esser Decilon slide rule
Date: copyright 1961
Inventory Number: 2003-1-0191
Classification: Slide Rule
Subject:
Maker: Keuffel & Esser Company (1867 - 1987)
Cultural Region:
Place of Origin:
Dimensions:
slide rule: 6.3 × 32.5 × 10 cm (2 1/2 × 12 13/16 × 3 15/16 in.)
leather case: 7.9 × 33.7 × 2.3 cm (3 1/8 × 13 1/4 × 7/8 in.)
Accessories: brown leather case with metal-reinforced flap closure
DescriptionRectangular mahogany slide rule faced with white xylonite (?), with three slides. The top and bottom slides are fixed to L-shaped pieces of metal at either end; the center slide moves from left to right. A glass runner with a vertical line down its center also moves left and right. The runner is in two parts, which are screwed together around the slides.
The front of the slide is printed with thirteen scales. Printed near the top of the top, fixed slide are two logarithmic scales, "Sq1" and "Sq2". "Sq1" (the top scale) carries values from 1 to 3.2; "Sq2" carries values from 3 to 10. Along the bottom of the same (top) slide is a logarithmic "DF" scale, with values ranging from 3 to 10 and from 1 to [pi].
Printed along the top of the center, moveable slide is a logarithmic "CF" scale, carrying values from 3 to 10 and from 1 to [pi]. Below this, printed in red, is an inverted logarithmic scale, "CIF", with values descending from 3.2 to 1 and from 10 to 3. Printed third from the top, along the same (center) slide, is an "L" scale, with values ranging from 0 to 1.
Printed in red fourth from the top along the center, moveable slide is an inverted logarithmic scale, "CI", with values descending from 10 to 1. Below this, printed along the bottom edge of the same 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, carrying values from 1 to 10. Below this, printed in red, are four "Ln" scales. "Ln0", printed second from the top of the bottom slide, carries values from 1.001 to 1.01. "Ln1", third from the top, has values ranging from 1.01 to 1.11. "Ln3" and "Ln4", fourth and fifth from the top, respectively, carry values ranging from 1.1 to 2.8 and from 2.6 to 3.
The back of the slide is also printed with thirteen scales. Printed near the top of the top, fixed slide are four inverted "Ln" scales. "Ln-3", near the top of the top slide, has values descending from .38 to .00003. Below this, "Ln-2" has values descending from .91 to .35. Third from the top is "Ln-1", with values descending from .99 to .90. Fourth from the top, "Ln-0", has values descending from .999 to .990.
Printed along the bottom edge of the top, fixed slide and the top edge of the center, moveable slide are scales for "A" and "B", respectively. Both are composed of two logarithmic scales (carrying values from 1 to 10) arranged side by side.
Printed second and fourth from the top along the center, moveable slide are, respectively, "T" and "S" scales. Both scales are marked with both ascending values (printed in black) and descending values (printed in red). On the "T" scale, the ascending values range from 5.6 to 45, and the descending values from 84.3 to 45. On the "S" scale, the ascending values range from 5.6 to 90, and the descending values from 84.3 to 0. Printed along the center of the same (center) slide is an "SRT" scale, with values ranging from .55 to 6.
Printed along the bottom edge of the center slide and along the top edge of the bottom, fixed slide are logarithmic scales carrying values from 1 to 10, "C" and "D", respectively.
Printed in red along the center of the bottom, fixed slide is an inverted logarithmic scale, "DI", with values descending from 10 to 1. Printed near the bottom of the same slide is a "K" scale, composed of three logarithmic scales (with values ranging from 1 to 10) placed side by side.
The front of the slide is printed with thirteen scales. Printed near the top of the top, fixed slide are two logarithmic scales, "Sq1" and "Sq2". "Sq1" (the top scale) carries values from 1 to 3.2; "Sq2" carries values from 3 to 10. Along the bottom of the same (top) slide is a logarithmic "DF" scale, with values ranging from 3 to 10 and from 1 to [pi].
Printed along the top of the center, moveable slide is a logarithmic "CF" scale, carrying values from 3 to 10 and from 1 to [pi]. Below this, printed in red, is an inverted logarithmic scale, "CIF", with values descending from 3.2 to 1 and from 10 to 3. Printed third from the top, along the same (center) slide, is an "L" scale, with values ranging from 0 to 1.
Printed in red fourth from the top along the center, moveable slide is an inverted logarithmic scale, "CI", with values descending from 10 to 1. Below this, printed along the bottom edge of the same 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, carrying values from 1 to 10. Below this, printed in red, are four "Ln" scales. "Ln0", printed second from the top of the bottom slide, carries values from 1.001 to 1.01. "Ln1", third from the top, has values ranging from 1.01 to 1.11. "Ln3" and "Ln4", fourth and fifth from the top, respectively, carry values ranging from 1.1 to 2.8 and from 2.6 to 3.
The back of the slide is also printed with thirteen scales. Printed near the top of the top, fixed slide are four inverted "Ln" scales. "Ln-3", near the top of the top slide, has values descending from .38 to .00003. Below this, "Ln-2" has values descending from .91 to .35. Third from the top is "Ln-1", with values descending from .99 to .90. Fourth from the top, "Ln-0", has values descending from .999 to .990.
Printed along the bottom edge of the top, fixed slide and the top edge of the center, moveable slide are scales for "A" and "B", respectively. Both are composed of two logarithmic scales (carrying values from 1 to 10) arranged side by side.
Printed second and fourth from the top along the center, moveable slide are, respectively, "T" and "S" scales. Both scales are marked with both ascending values (printed in black) and descending values (printed in red). On the "T" scale, the ascending values range from 5.6 to 45, and the descending values from 84.3 to 45. On the "S" scale, the ascending values range from 5.6 to 90, and the descending values from 84.3 to 0. Printed along the center of the same (center) slide is an "SRT" scale, with values ranging from .55 to 6.
Printed along the bottom edge of the center slide and along the top edge of the bottom, fixed slide are logarithmic scales carrying values from 1 to 10, "C" and "D", respectively.
Printed in red along the center of the bottom, fixed slide is an inverted logarithmic scale, "DI", with values descending from 10 to 1. Printed near the bottom of the same slide is a "K" scale, composed of three logarithmic scales (with values ranging from 1 to 10) placed side by side.
Signedface, center slide, left center: ©1947, 1961 By / KEUFFEL & ESSER CO.;
face, center slide, right: [K&E trademark];
case, on flap: [K&E trademark]
face, center slide, right: [K&E trademark];
case, on flap: [K&E trademark]
Inscribedface, top slide, right: [Deci-lon trademark] / 68 1100;
face, bottom slide, right: 0.001 to 0.01 / 0.01 to 0.10 / 0.1 to 1.0 / 1.0 to 10.0;
back, top slide, left: 244;
back, center slide, left: C.... / 066244;
back, bottom slide, left: 244;
back, top slide, right: -1.0 to -10.0 / -0.1 to -1.0 / -0.01 to -0.10 / -0.001 to -0.01;
back, center slide, right: U.S. PAT'S 2,422,649 / 2,500,460 2,534,695;
back, bottom slide, right: [Deci-lon trademark] / MADE IN U.S.A.;
case, below flap: [Deci-lon trademark]
face, bottom slide, right: 0.001 to 0.01 / 0.01 to 0.10 / 0.1 to 1.0 / 1.0 to 10.0;
back, top slide, left: 244;
back, center slide, left: C.... / 066244;
back, bottom slide, left: 244;
back, top slide, right: -1.0 to -10.0 / -0.1 to -1.0 / -0.01 to -0.10 / -0.001 to -0.01;
back, center slide, right: U.S. PAT'S 2,422,649 / 2,500,460 2,534,695;
back, bottom slide, right: [Deci-lon trademark] / MADE IN U.S.A.;
case, below flap: [Deci-lon trademark]
FunctionFor solving mathematics problems, including trigonometric problems, as well as problems involving logarithms, squares, square roots, cubes, cube roots, and higher powers and roots.
Curatorial RemarksIdentical to 1995-1-0024.
This slide rule, like the Polyphase Duplex rules listed in K&E's 1956 catalog, is likely made of mahogany with a xylonite (?) facing.
No image of back of rule.
This slide rule, like the Polyphase Duplex rules listed in K&E's 1956 catalog, is likely made of mahogany with a xylonite (?) facing.
No image of back of rule.
Primary Sources"Deci-lon: An Instruction Manual." New York: Keuffel & Esser Co., 1962. Available for download Available for download here.
ProvenancePrivate Donor, Troy, New York.
