Keuffel & Esser Log Log Duplex slide rule
Date: ca. 1915-1923
Inventory Number: 1997-1-2006
Classification: Slide Rule
Subject:
Maker: Keuffel & Esser Company (1867 - 1987)
Owner: Benjamin Martin Shaub (1893 - 1993)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
slide rule: 1.2 × 31.9 × 5.1 cm (1/2 × 12 9/16 × 2 in.)
leather case: 6.8 × 33 × 2.9 cm (2 11/16 × 13 × 1 1/8 in.)
Accessories: Brown leather case with flap closure, for storage
Bibliography:
Catalogue of Keuffel & Esser Co.
DescriptionRectangular slide rule faced with white celluloid (?), 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 face of the rule is printed with eight scales. Along the center of the top, fixed slide is a "K" scale composed of three logarithmic scales (values 1 to 10) arranged side by side. Printed along the bottom edge of the top slide and along the top edge of the center, moveable slide, are two logarithmic scales: "DF" and "CF", respectively. These have values ranging from [pi] to 10 and from 1 to [pi].
Printed second from the top along the second slide is an inverted logarithmic "CIF" scale, with values descending from 3.2 to 1 and from 10 to 3.1. Third from the top along the same (center) slide, is an inverted logarithmic scale, "CI".
Printed along the bottom edge of the center, moveable slide and along the top edge of the bottom, fixed slide are two logarithmic scales (values 1 to 10): "C" and "D", respectively. Printed below the "D" scale is an "L" scale, with values ranging from 0 to 10.
Nine scales are printed on the back of the slide rule. Near the center of the top, fixed slide is a scale for "LL0", with values descending from e to .06, then from .97 to e. Printed along the bottom edge of the top slide and along the top edge of the center, moveable slide are "A" and "B" scales, respectively, composed of two logarithmic scales (values 1 to 10) arranged side by side.
Printed second from the top on the center slide is an "S" scale, with values ranging from 34' to 90°. Third from the top on the center slide is a "T" scale, carrying values from 5.5 to 45.
Printed along the bottom of the second slide is a logarithmic "C" scale, carrying values from 1 to 10. Printed along the top of the bottom, moveable slide is an "LL3" scale, with values ranging from e to 20,000. Below this is an "LL2" scale, with values ranging from 1.1 to e. Near the bottom of the bottom, fixed slide is an "LL1" scale, carrying values from 1.01 to 1.1.
The slide rule is stored in a brown leather case with flap closure.
The face of the rule is printed with eight scales. Along the center of the top, fixed slide is a "K" scale composed of three logarithmic scales (values 1 to 10) arranged side by side. Printed along the bottom edge of the top slide and along the top edge of the center, moveable slide, are two logarithmic scales: "DF" and "CF", respectively. These have values ranging from [pi] to 10 and from 1 to [pi].
Printed second from the top along the second slide is an inverted logarithmic "CIF" scale, with values descending from 3.2 to 1 and from 10 to 3.1. Third from the top along the same (center) slide, is an inverted logarithmic scale, "CI".
Printed along the bottom edge of the center, moveable slide and along the top edge of the bottom, fixed slide are two logarithmic scales (values 1 to 10): "C" and "D", respectively. Printed below the "D" scale is an "L" scale, with values ranging from 0 to 10.
Nine scales are printed on the back of the slide rule. Near the center of the top, fixed slide is a scale for "LL0", with values descending from e to .06, then from .97 to e. Printed along the bottom edge of the top slide and along the top edge of the center, moveable slide are "A" and "B" scales, respectively, composed of two logarithmic scales (values 1 to 10) arranged side by side.
Printed second from the top on the center slide is an "S" scale, with values ranging from 34' to 90°. Third from the top on the center slide is a "T" scale, carrying values from 5.5 to 45.
Printed along the bottom of the second slide is a logarithmic "C" scale, carrying values from 1 to 10. Printed along the top of the bottom, moveable slide is an "LL3" scale, with values ranging from e to 20,000. Below this is an "LL2" scale, with values ranging from 1.1 to e. Near the bottom of the bottom, fixed slide is an "LL1" scale, carrying values from 1.01 to 1.1.
The slide rule is stored in a brown leather case with flap closure.
Signedface, bottom slide, bottom left: KEUFFEL & ESSER CO. N.Y.;
rider, bottom edge: KEUFFEL & ESSER CO. N.Y.
rider, bottom edge: KEUFFEL & ESSER CO. N.Y.
Inscribedface, center slide, right: <4092-3>;
face, bottom slide, bottom center: PAT. JUNE 5.'00 DEC. 22.'08 APR. 1.'24;
face, bottom slide, bottom right: MADE IN U.S.A.;
back, center slide, left: 102525;
back, center slide, etched to right of "B" scale: S;
back, center slide, etched to right of "C" scale: T;
top edge of top slide, left: 102525;
top edge of runner: PATENT 2,086,502;
case, embossed on flap: 4092-3S;
written on case: B. M. Schaub / Sibley College
face, bottom slide, bottom center: PAT. JUNE 5.'00 DEC. 22.'08 APR. 1.'24;
face, bottom slide, bottom right: MADE IN U.S.A.;
back, center slide, left: 102525;
back, center slide, etched to right of "B" scale: S;
back, center slide, etched to right of "C" scale: T;
top edge of top slide, left: 102525;
top edge of runner: PATENT 2,086,502;
case, embossed on flap: 4092-3S;
written on case: B. M. Schaub / Sibley College
FunctionFor solving mathematics problems, particularly those involving fractional roots or powers, or logarithms.
For details on using the slide rule to solve particular problems, see William E. Breckenridge's manual, available for download here.
For details on using the slide rule to solve particular problems, see William E. Breckenridge's manual, available for download here.
Historical AttributesUsed by B. M. Shaub while at Sibley College, Cornell, while studying Mechanical Engineering, graduated 1923.
Primary Sources"Log Log Duplex Slide Rules." Catalogue of Keuffel & Esser Co. 38 (1936): 318-19.
Breckenridge, William E. "The Log Log Duplex Slide Rule." New York: Keuffel & Esser, 1926.
Breckenridge, William E. "The Log Log Duplex Slide Rule." New York: Keuffel & Esser, 1926.
ProvenanceUsed by Prof. Benjamin M. Shaub, Department of Geology, Smith College, Northampton, MA 01063. Prof. Shaub gifted a total of 11 instruments to the Collection, inventory #s 1997-1-1997 thru 1997-1-2007