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Date: 1915-1919

Inventory Number: 1989-1-0006

Classification: Slide Rule

Subject:

Maker: Gilson Slide Rule Company (1915-circa 1975)

Cultural Region:

Place of Origin:

Dimensions:

1.4 × 8.7 × 8.4 cm (9/16 × 3 7/16 × 3 5/16 in.)

DescriptionMetal disc with yellowed paint and two celluloid (?) cursors of different lengths, joined at the center by a large, cross-shaped bolt. Both cursors are attached to the disc's face.

Six scales are printed around the circumference of the face of the disc. The unlabeled outermost scale is a logarithmic scale carrying values from 10 to 100. Inside this is another unlabeled scale carrying values 0 to 100. Third from the outside is a "SINES" scale with values ascending from 0 to 1. Inside this is a scale for "TANGENTS" carrying values from 0 to 100. Fifth from the outside is a scale with fractional values from 0 to 1. The innermost scale, for "COS. & COT.", has values descending from 90 to 0.

A circle divided into quarters is drawn on the back of the disc. The dividing lines are labeled, clockwise, 0°, 270°, 180°, and 90°. Inside each quadrant are notations for the following trigonometric functions: SIN - COS + TAN - COT - (in the quadrant to the right of the 0° line); SIN - COS - TAN + COT + (in the next quadrant, clockwise); SIN + COS - TAN - COT - (in the next quadrant, clockwise); and SIN + COS + TAN + COT + (in the quadrant to the left of the 0° line).

Six scales are printed around the circumference of the face of the disc. The unlabeled outermost scale is a logarithmic scale carrying values from 10 to 100. Inside this is another unlabeled scale carrying values 0 to 100. Third from the outside is a "SINES" scale with values ascending from 0 to 1. Inside this is a scale for "TANGENTS" carrying values from 0 to 100. Fifth from the outside is a scale with fractional values from 0 to 1. The innermost scale, for "COS. & COT.", has values descending from 90 to 0.

A circle divided into quarters is drawn on the back of the disc. The dividing lines are labeled, clockwise, 0°, 270°, 180°, and 90°. Inside each quadrant are notations for the following trigonometric functions: SIN - COS + TAN - COT - (in the quadrant to the right of the 0° line); SIN - COS - TAN + COT + (in the next quadrant, clockwise); SIN + COS - TAN - COT - (in the next quadrant, clockwise); and SIN + COS + TAN + COT + (in the quadrant to the left of the 0° line).

Signedface of disc, printed around bolt: PATENTS PENDING GILSON SLIDE RULE CO., NILES, MICH.

FunctionTo solve mathematics problems, including multiplication, division, squares, square roots, and trigonometric problems.

This appears to be an early version of the Gilson Midget slide rule, which was patented in 1919. See related works for information on the development of the Midget.

This appears to be an early version of the Gilson Midget slide rule, which was patented in 1919. See related works for information on the development of the Midget.

Curatorial RemarksSee a later version of the Midget, manufactured by Gilson and distributed by Tavella Sales Co.: 1990-4-0001.

Related WorksAldinger, Henry, and Ed Chamberlain. "Gilson Slide Rules--Part I--The Small Rules." *Journal of the Oughtred Society* 9, no. 1 (Spring 2000): 48-60.

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