The Frederick Post Versalog Catalog No. 1460 is a precision duplex slide rule designed for engineering, scientific and technical calculations.
Before performing calculations, the user must understand the physical layout of the instrument and the purpose of each scale. A slide rule is not a collection of unrelated markings. Each scale represents a mathematical relationship that allows specific calculations to be performed efficiently.
The Duplex Slide Rule Design
The Post Versalog 1460 is a duplex slide rule. A duplex slide rule contains useful scales on both the front and rear surfaces, allowing advanced calculations without requiring multiple instruments.
- Fixed body.
- Movable slide.
- Cursor.
- Hairline.
- Front scales.
- Rear scales.
Main Components
Body
The body is the fixed outer frame of the slide rule. Fixed scales are printed on the body and provide the reference position for calculations.
Slide
The slide is the movable centre section. Moving the slide changes the relationship between logarithmic scales and allows mathematical operations to be performed.
Cursor and Hairline
The cursor is the transparent indicator that moves along the length of the instrument. The hairline provides the precise reference point used to transfer values between scales.
Scale Identification
The Versalog 1460 contains specialised scales for arithmetic, powers, roots, logarithms, trigonometry and exponential calculations.
- C scale: multiplication and division.
- CI scale: reciprocal calculations and efficient division.
- D scale: primary reference scale.
- A and B scales: squares and square roots.
- K scale: cubes and cube roots.
- CF and DF scales: folded scales for calculations involving π.
- S, T and ST scales: trigonometric calculations.
- L scale: logarithms.
- LL scales: exponential calculations.
Using Scale Names
The letters printed on a slide rule are not labels for decoration. They identify mathematical relationships. Understanding these relationships allows the user to select the correct scale before beginning a calculation.
Recommended Diagrams
- Complete labelled view of the Post Versalog 1460.
- Front scale identification diagram.
- Rear scale identification diagram.
- Cursor and hairline detail.
- Fixed versus movable scale illustration.
All diagrams for this guide should follow the Greyscale Zone design standard:
- Black-and-white engineering style.
- High contrast.
- Printable on monochrome printers.
- No colour-dependent information.
- Clear labels and accessible descriptions.
Continue Learning
Continue to Versalog 1460 Reading Scales.