Versalog 1460 Glossary
This glossary provides definitions for the terms, scales and techniques used throughout the Greyscale Guide to the Post Versalog 1460.
Accuracy
The degree to which a calculated result represents the true value. On a slide rule, accuracy depends on scale length, reading technique, cursor alignment and estimation.
Antilogarithm
The reverse operation of a logarithm. An antilogarithm converts a logarithmic value back into its original number.
C Scale
The movable logarithmic scale primarily used with the D scale for multiplication and division.
Characteristic
The whole-number portion of a common logarithm. The characteristic determines the order of magnitude of the original number.
CI Scale
C Inverted. The C scale printed in reverse order. The CI scale represents reciprocal relationships and is useful for efficient division and continuous calculations.
CF Scale
The folded version of the C scale. The CF scale is shifted to simplify calculations involving π and related engineering formulas.
Cursor
The transparent movable indicator containing a hairline used to transfer values between slide rule scales.
Decimal Placement
The process of determining the correct magnitude of a result. Slide rules provide significant digits but do not automatically display decimal points.
DF Scale
The folded version of the D scale. Used with CF for efficient engineering calculations.
D Scale
The primary fixed logarithmic scale used as the reference for many slide rule calculations.
Estimation
The mental calculation performed before using the slide rule to predict the approximate range of the answer.
Folded Scales
Logarithmic scales shifted from the standard position to reduce slide movement and improve calculation efficiency.
Index
The 1.0 marking at the beginning or end of a logarithmic scale used as an alignment reference.
Interpolation
The process of estimating values between printed scale markings.
K Scale
The cube scale used for finding cubes and cube roots.
L Scale
The linear logarithm scale used for reading common logarithmic values.
Logarithm
A mathematical value representing the exponent required to produce a number from a given base.
Log-Log Scale
A specialised logarithmic scale used for exponential calculations, fractional powers and non-integer roots.
Mantissa
The fractional portion of a common logarithm. The mantissa determines the significant digits of the original number.
Reciprocal
The value obtained by dividing 1 by a number. For example, the reciprocal of 4 is 0.25.
Significant Figures
The meaningful digits that represent the precision of a measurement or calculation.
Slide
The movable central section of a slide rule containing the movable scales.
Slide Rule
A mechanical calculating instrument based on logarithmic relationships that allows multiplication, division, powers, roots and specialised calculations.
ST Scale
The small-angle trigonometric scale used for sine and tangent calculations near zero degrees.
T Scale
The trigonometric scale used for tangent calculations.
Trigonometric Scales
Scales used to solve angle-based problems, including sine, tangent and related relationships.
Continue Learning
Return to The Greyscale Guide to the Post Versalog Slide Rule to continue through the complete Versalog 1460 series.