Darnley's patent rotatable lightning calculator
Category
Metalwork
Date
circa 1921
Materials
Tinplate
Measurements
9.25 ins (l)1.25 ins (dia)
Order this imageCollection
Shaw's Corner, Hertfordshire
NT 1274959
Summary
A Darnley's rotatable calculator, in the form of a cylindrical tin plate pencil case with removable end cap and rotatable sleeve. The sleeve can be rotated to perform multiplications, up to 20 x 20, the results being displayed through openings in the sleeve. The sleeve painted blue with black and white markings including a 6 inch scale, graduated in 1/8 inch. End caps painted silver. Circa 1921. On the sleeve - "DARNLEY'S PATENT ROTATABLE LIGHTNING CALCULATOR, PENCIL CASE, RULER and MEASURE. / SOLELY MANUFACTURED IN ENGLAND." Figure of scholar with REGD TRADE MARK below.
Full description
A Darnley’s rotatable calculator, circa 1921. Bernard Shaw was interested in different types of gadgets and mechanical devices. The cap at one end is removable, allowing the storage of pencils within the cylinder. Shaw’s fellow Fabian Beatrice Webb was struck by Shaw’s technical knowledge of things. And his biographer Hesketh Pearson recalled: “Shaw had a Kiplingesque love of knowing how things were done; technicalities delighted him…Machine tools of all kinds interested him; and so did pianolas, gramophones, wireless, and calculators…” (Hesketh Pearson, Bernard Shaw: His Life and Personality, 1942, p.315). The miniature wall-mounted tool box similarly bears testament to this practical side of Shaw’s personality. (Alice McEwan, 2020)
Provenance
The Shaw Collection. The house and contents were bequeathed to the National Trust by George Bernard Shaw in 1950, together with Shaw's photographic archive.
Marks and inscriptions
On the sleeve - "DARNLEY'S PATENT ROTATABLE LIGHTNING CALCULATOR, PENCIL CASE, RULER and MEASURE. / SOLELY MANUFACTURED IN ENGLAND." Figure of scholar with REGD TRADE MARK below