Fearns Universal Metric Converter slide rule

Fearns Universal Metric ConverterFearns Universal Metric Converter
made in England, 1970s

Fearns started manufacturing special purpose scale rules for industrial application in 1947. They are well known for their circular scale rules- like this one- which was imported into Australia in the 70s when the country covered to the metric system. The rule is model #A7.

The circular slide rule comes in its original vinyl [circular] case – and has instructions for use printed on the back. I am very fond of scale rules, linear and circular- and so snapped up this example; it’s in very good condition and still useful today for quick and efficient metric conversion calculations.

In researching the slide rule I found a number of sites dedicated to the collection of slide rules- and circular slides rules- and indeed Fearns circular slide rules. These useful, technical devices are now very collectible and have a huge fan base. I am not alone in my adoration of slide rules!

The circular slide rule is for sale: $AUD40

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