Log Log Duplex Decitrig slide rule
Datecirca 1943
Inventory Number1995-1-0023
ClassificationSlide Rule
Subject
Maker
Keuffel & Esser Company
1867 - 1987
Cultural Region
Place of Origin
Dimensionsslide rule: 5 × 31.8 × 1.1 cm (1 15/16 × 12 1/2 × 7/16 in.)
case: 6.4 × 33.4 × 3.2 cm (2 1/2 × 13 1/8 × 1 1/4 in.)
case: 6.4 × 33.4 × 3.2 cm (2 1/2 × 13 1/8 × 1 1/4 in.)
Material
Accessoriesblack leather case with flap closure
Bibliography
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.
Ten scales are printed on the face of the rule. Near the top of the top, fixed slide is an "L" scale, carrying values from 0 to 1. Printed near the middle of the same (top) slide is a scale for "LL1," carrying values from 1.01 to 1.15.
Along the bottom edge of the top, fixed slide and the top edge of the center, moveable slide are, respectively, scales for "DF" and CF". Both carry values from [pi] to 10, and then from 1 to [pi]. Printed in red along the center of the center, moveable slide are scales for "CIF" (top) and "CI" (bottom. Both are inverted logarithmic scales; "CIF" descends from 3.2 to 1, and then from 10 to 3.1. "CI" has values descending from 10 to 1.
Printed along the bottom edge of the center, moveable slide and the top edge of the bottom, fixed slide on the face of the rule are, respectively, "C" and "D" scales. These are logarithmic scales carrying values from 1 to 10. Below the "D" scale is an "LL3" scale, carrying values from [e] to 20,000. Printed near the bottom of the bottom slide is a scale for "LL2," carrying values from 1.11 to [e].
Ten additional scales are printed on the back of the rule. Near the top of the top, fixed slide is an "LL00" scale, with values descending from 90 to 0. Along the center of the top slide is an "LL0" scale, with values descending from 999 to 91.
Printed along the bottom edge of the top, fixed slide and the top edge of the center, moveable slide are, respectively, "A" and "B" scales. These are both composed of two logarithmic scales (carrying values from 1 to 10) placed side by side.
Printed second from the top along the center, moveable slide, and along the bottom edge of the same (center) 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 third from the top along the center, moveable slide on the face of the rule is an "ST" scale, carrying values from .58 to 5.7. Printed along the top edge of the bottom, fixed slide is a logarithmic "D" scale, carrying values from 1 to 10. Printed in red near the center of the same (bottom) slide is an inverted logarithmic scale, "DI". Near the bottom of the bottom slide is printed a "K" scale, composed of three logarithmic scales (carrying values from 1 to 10) placed side by side.
The slide rule is stored in a black leather case with metal-reinforced flap closure.
Ten scales are printed on the face of the rule. Near the top of the top, fixed slide is an "L" scale, carrying values from 0 to 1. Printed near the middle of the same (top) slide is a scale for "LL1," carrying values from 1.01 to 1.15.
Along the bottom edge of the top, fixed slide and the top edge of the center, moveable slide are, respectively, scales for "DF" and CF". Both carry values from [pi] to 10, and then from 1 to [pi]. Printed in red along the center of the center, moveable slide are scales for "CIF" (top) and "CI" (bottom. Both are inverted logarithmic scales; "CIF" descends from 3.2 to 1, and then from 10 to 3.1. "CI" has values descending from 10 to 1.
Printed along the bottom edge of the center, moveable slide and the top edge of the bottom, fixed slide on the face of the rule are, respectively, "C" and "D" scales. These are logarithmic scales carrying values from 1 to 10. Below the "D" scale is an "LL3" scale, carrying values from [e] to 20,000. Printed near the bottom of the bottom slide is a scale for "LL2," carrying values from 1.11 to [e].
Ten additional scales are printed on the back of the rule. Near the top of the top, fixed slide is an "LL00" scale, with values descending from 90 to 0. Along the center of the top slide is an "LL0" scale, with values descending from 999 to 91.
Printed along the bottom edge of the top, fixed slide and the top edge of the center, moveable slide are, respectively, "A" and "B" scales. These are both composed of two logarithmic scales (carrying values from 1 to 10) placed side by side.
Printed second from the top along the center, moveable slide, and along the bottom edge of the same (center) 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 third from the top along the center, moveable slide on the face of the rule is an "ST" scale, carrying values from .58 to 5.7. Printed along the top edge of the bottom, fixed slide is a logarithmic "D" scale, carrying values from 1 to 10. Printed in red near the center of the same (bottom) slide is an inverted logarithmic scale, "DI". Near the bottom of the bottom slide is printed a "K" scale, composed of three logarithmic scales (carrying values from 1 to 10) placed side by side.
The slide rule is stored in a black leather case with metal-reinforced flap closure.
Signedface, top slide, top left: KEUFFEL & ESSER CO. N.Y.
bottom edge of rider: KEUFFEL & ESSER CO.
flap of case: [K&E trademark]
Inscribedtop slide, top center: PATS. RE.20,984 1,930,852 2,168,056 2170,144 PAT. PEND.;
top slide, top right: MADE IN U.S.A.;
center slide, left: 408782;
center slide, right: <4081-3>;
top edge of rider: PATENT 2,086,502;
top edge of top slide, left: 408782
Curatorial RemarksSame model as 1990-5-0004, though made at different date. See, ex., placement of serial number.
FunctionFor solving mathematics problems, including trigonometric problems, problems containing combinations of three factors, as well as problems involving squares, square roots, cubes, cube roots, and higher powers and roots. Log log scales are meant to making solving problems involving exponents easier. On Keuffel & Esser's "Decitrig" slide rules, the trigonometrical scales are divided to represent degrees and decimals of a degree.
For details on using the rule to solve particular problems, see instruction booklet in instrument file 1990-5-0004.
For details on using the rule to solve particular problems, see instruction booklet in instrument file 1990-5-0004.
ProvenanceLyman Laboratory, Department of Physics, Harvard University; transferred to CHSI on November 9, 1995 via Prof. Robert V. Pound.
Keuffel & Esser Company
Date: dated 1943
Accessories: instruction book and black leather case with flap closure, for storage
Object number: 1990-5-0004
Keuffel & Esser Company
Date: circa 1956
Accessories: brown leather case with metal-reinforced flap closure
Object number: 1995-1-0025
Keuffel & Esser Company
Date: copyright 1961
Accessories: brown leather case with metal-reinforced flap closure
Object number: 2003-1-0191
Keuffel & Esser Company
Date: copyright 1961
Accessories: Brown leather case with metal-reinforced flap closure, for storage.
Object number: 1995-1-0024
Pickett & Eckel, Inc.
Date: after 1964
Accessories: brown leather case with belt clip
Object number: 1991-4-0004c
Pickett & Eckel, Inc.
Date: copyright 1959
Accessories: brown leather case with hard plastic lining and flap closure; small plastic bag; Twin Pack box; 3 instruction manuals (in file); belt loop (1991-4-0004b); pocket slide rule (1991-4-0004c); cardboard box
Object number: 1991-4-0004a
Hemmi
Date: 1971
Accessories: brown leather case with glap closure; brown leather loop for attachment to belt
Object number: 1989-1-0009
Keuffel & Esser Company
Date: copyright 1947
Accessories: brown leather case, with metal-reinforced belt clip
Object number: 1997-1-0971
Pickett & Eckel, Inc.
Date: circa 1951
Accessories: brown leather case with table of equivalents
Object number: 2004-1-0341
Keuffel & Esser Company
Date: circa 1935
Accessories: card describing use; brown leather case with metal-reinforced flap closure, for storage
Object number: 1997-1-2005
Keuffel & Esser Company
Date: ca. 1915-1923
Accessories: Brown leather case with flap closure, for storage
Object number: 1997-1-2006
Eugene Dietzgen Company
Date: 1941-1952
Accessories: black leather case with flap closure
Object number: 2007-1-0142
See also/See also
