# Pickett Model N600-ES Log Log Speed Rule

### Title

Pickett Model N600-ES Log Log Speed Rule

### Subject

Engineering; Mechanical Engineering; Mathematics

### Description

Physical Description:

The Pickett Model N600-ES Log Log slide rule is constructed using three yellow painted aluminum bars. The “ES” in the model name means “Eye-Saver” and refers to the yellow painted construction. The two outer bars are called the stators and are attached by a brace on both ends. The braces create a gap between the two stators where the third aluminum bar, called the slide, fits into the grooves between the two stators. A clear plastic cursor slides along the outside of the stators. The cursor has a vertical hairline marker on both sides of the slide rule for lining up the scales between the slide and stators. The upper stator has LL1 and A scales on the front side and LL2 and DF scales on the backside. The lower stator has D, DI, and K scales on the front side and D and LL3 scales on the backside. The slide has B, ST, T, S, and C scales on the front side and CF, Ln, L, CI, and C scales on the backside. The scales are usually logarithmic with a few exceptions such as the L and Ln scale which are log operations with a linear scale. The index of a scale is the furthest left number for the left index or the furthest right number for the right index. The scale ranges and operations are described under inscriptions.

Functional Description:

The Pickett Model N600-ES Log Log slide rule is a duplex slide rule. A duplex slide rule has scales on both sides of the slide rule and a dual-faced cursor. The dual-faced cursor allows for relating one side of the scale to the other side for a greater number of calculations. Logarithmic scales have a multiplication and division property discovered by William Oughtred in 1630 that allow for the operations of multiplication and division instead of addition and subtraction of linear scales. Multiplication is the simplest operation on a slide rule using the two fundamental scales, C and D. To multiply two numbers, x and y, the left index of C is positioned over x on the D scale. Then the cursor is position over y on the C scale. The value of the cursor on the D scale is the solution to x multiplied by y. The decimal place may need to be adjusted to get the correct order of magnitude since the C and D scale has values ranging from 1 to 10. The other scales are used to perform different operations such as squares, reciprocals, exponentials, and sines, cosines, and tangents.

The Pickett Model N600-ES Log Log slide rule is constructed using three yellow painted aluminum bars. The “ES” in the model name means “Eye-Saver” and refers to the yellow painted construction. The two outer bars are called the stators and are attached by a brace on both ends. The braces create a gap between the two stators where the third aluminum bar, called the slide, fits into the grooves between the two stators. A clear plastic cursor slides along the outside of the stators. The cursor has a vertical hairline marker on both sides of the slide rule for lining up the scales between the slide and stators. The upper stator has LL1 and A scales on the front side and LL2 and DF scales on the backside. The lower stator has D, DI, and K scales on the front side and D and LL3 scales on the backside. The slide has B, ST, T, S, and C scales on the front side and CF, Ln, L, CI, and C scales on the backside. The scales are usually logarithmic with a few exceptions such as the L and Ln scale which are log operations with a linear scale. The index of a scale is the furthest left number for the left index or the furthest right number for the right index. The scale ranges and operations are described under inscriptions.

Functional Description:

The Pickett Model N600-ES Log Log slide rule is a duplex slide rule. A duplex slide rule has scales on both sides of the slide rule and a dual-faced cursor. The dual-faced cursor allows for relating one side of the scale to the other side for a greater number of calculations. Logarithmic scales have a multiplication and division property discovered by William Oughtred in 1630 that allow for the operations of multiplication and division instead of addition and subtraction of linear scales. Multiplication is the simplest operation on a slide rule using the two fundamental scales, C and D. To multiply two numbers, x and y, the left index of C is positioned over x on the D scale. Then the cursor is position over y on the C scale. The value of the cursor on the D scale is the solution to x multiplied by y. The decimal place may need to be adjusted to get the correct order of magnitude since the C and D scale has values ranging from 1 to 10. The other scales are used to perform different operations such as squares, reciprocals, exponentials, and sines, cosines, and tangents.

### Creator

Gideon Hoekstra, Nick Renke, Donovan Doran, Erik Madson

### Date

1962

### Language

English

### Physical Dimensions

Minimum: 152.4mm X 38.1mm X 7.9mm

Maximum Extended: 279.4mm X 38.1mm X 7.9mm

Maximum Extended: 279.4mm X 38.1mm X 7.9mm

### Materials

Aluminum, Plastic

### Maker

Pickett & Eckel - Chicago, Illinois, US

### Inscriptions

MODEL | N600-ES | LOG LOG | SPEED RULE | PICKETT | MADE IN USA | PICKETT | ALL METAL | SLIDE RULES | PICKETT & ECKEL. | INC. | CHICAGO, ILL | © 1962

Scale Label Inscription in Order (Description, Function, Range)

LL1 (Log Log, e0.01x, greater than 1: 1.01-1.15 and less than 1: descending 0.99-0.91, Logarithmic) |

A (Scale of squares, x2, two repeated 1-10 scales, Logarithmic) |

B (Scale of Squares, x2, two repeated 1-10 scales, Logarithmic) |

ST (Scale of sines and tangents, sin(x) tan(x), 0.6-5.5, Logarithmic) |

T (Scale of tangents and cotangents, tan(x) cot(x), 6-45 ascending and 84-45 descending, Logarithmic) |

S (Scale of sines and cosines, sin(x) cos(x), 5.8-90 ascending and 20-84 descending, Logarithmic) |

C (Fundamental Slide Rule Scale, x, 1-10, Logarithmic) |

D (Fundamental Slide Rule Scale, x, 1-10, Logarithmic) |

DI (Reciprocal D scale, 1/x, descending 1-10, Logarithmic) |

K (Scale of cubes, x3, three repeated 1-10 scales, Logarithmic) |

LL2 (Log Log, e0.1x, greater than 1: 1.11-e and less than 1: descending 0.90-0.40, Logarithmic) |

DF (Folded D scale, x*pi, pi-10 then 1-pi, Logarithmic) |

CF (Folded C scale, x*pi, pi-10 then 1-pi, Logarithmic) |

Ln (Natural log scale, ln(x), 0-2.3, Linear) |

L (Log scale, log(x), 1-10, Linear) |

CI (Reciprocal C scale, 1/x, descending 1-10, Logarithmic) |

C (Repeated) |

D (Repeated) |

LL3 (Log Log, ex, greater than 1: e-20M and less than 1: descending 0.37-0.0001, Logarithmic)

Scale Label Inscription in Order (Description, Function, Range)

LL1 (Log Log, e0.01x, greater than 1: 1.01-1.15 and less than 1: descending 0.99-0.91, Logarithmic) |

A (Scale of squares, x2, two repeated 1-10 scales, Logarithmic) |

B (Scale of Squares, x2, two repeated 1-10 scales, Logarithmic) |

ST (Scale of sines and tangents, sin(x) tan(x), 0.6-5.5, Logarithmic) |

T (Scale of tangents and cotangents, tan(x) cot(x), 6-45 ascending and 84-45 descending, Logarithmic) |

S (Scale of sines and cosines, sin(x) cos(x), 5.8-90 ascending and 20-84 descending, Logarithmic) |

C (Fundamental Slide Rule Scale, x, 1-10, Logarithmic) |

D (Fundamental Slide Rule Scale, x, 1-10, Logarithmic) |

DI (Reciprocal D scale, 1/x, descending 1-10, Logarithmic) |

K (Scale of cubes, x3, three repeated 1-10 scales, Logarithmic) |

LL2 (Log Log, e0.1x, greater than 1: 1.11-e and less than 1: descending 0.90-0.40, Logarithmic) |

DF (Folded D scale, x*pi, pi-10 then 1-pi, Logarithmic) |

CF (Folded C scale, x*pi, pi-10 then 1-pi, Logarithmic) |

Ln (Natural log scale, ln(x), 0-2.3, Linear) |

L (Log scale, log(x), 1-10, Linear) |

CI (Reciprocal C scale, 1/x, descending 1-10, Logarithmic) |

C (Repeated) |

D (Repeated) |

LL3 (Log Log, ex, greater than 1: e-20M and less than 1: descending 0.37-0.0001, Logarithmic)

### History of the Object

Slides rules were used in math intensive engineering courses to perform calculations. Slides rules were eventually replaced by calculators and are now mostly obsolete.

### Location

MEEM, Third floor display case, 3rd case from the right, 2nd shelf

### Bibliography

MacKenzie, D. Scott. “Illustrated Self-Guided Course On How To Use The Slide Rule.” Sliderulermuseum. November 18, 2019. https://www.sliderulemuseum.com/SR_Course.htm

Marcotte, Eric. “Types of Slide Rules and their Scales.” Sliderule. November 18, 2019. https://www.sliderule.ca/scales.htm

Marcotte, Eric. “Types of Slide Rules and their Scales.” Sliderule. November 18, 2019. https://www.sliderule.ca/scales.htm

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## Collection

## Citation

Gideon Hoekstra, Nick Renke, Donovan Doran, Erik Madson, “Pickett Model N600-ES Log Log Speed Rule,”

*Michigan Tech Inventory of Historic Scientific Instruments*, accessed April 17, 2021, https://ihsi.omeka.net/items/show/185.