Farmar's slide rule

Farmar's slide rule

Slide Rules

The Museum has the largest display of slide rules in the UK, courtesy of the UK Slide Rule Circle. Fifty different slide rules show the development of these devices over four centuries.

Invented in the 1620s soon after the publication of concept of the logarithm, slide rules were in use right up to the 1980s although their decline began in the 1960s with the advent of electronic calculators and computers.

Popular with the taxman across the centuries for calculating the volume of spirits in barrels, slide rules come in all shapes and sizes. There is even one on display that can calculate the amount of meat on a cow!


Madas mechanical calculator 1913

Madas mechanical calculator 1913

Calculators

The mechanical adding machine was invented in the seventeenth century, the familiar push button machine arrived in the twentieth century and in the 1950s transistor technology enabled the development of fully electronic calculators. By the 1970s, they had become pocket-sized. The Museum has an array of calculators from across the years.