• Fowler's (Calculators) Limited (manufacturer)

Fowler "12-10" calculator in a leather case, with instruction booklet

early 20th century

- The calculator is made up of three discs, two moveable and one fixed. The bottom disc is printed with seven concentric scales and is rotated using the top knob. The middle disc is clear plastic imprinted with a single black line and is rotated using the upper right knob. The top disc is the fixed protective shield, imprinted with a red line. Following the instructions in the accompanying booklet, DR1991:0021:002, the compass can be manipulated to perform calculations and conversions in much the same manner as a slide rule.

Printed instruction booklet on wove paper

artefact (body circular): 8.6 x 8.6 cm (3 3/8 x 3 3/8 in.) artefact (exterior diameter): 12.4 x 12.4 cm (4 7/8 x 4 7/8 in.) artefact (case): 12.2 x 11 x 2.5 cm (4 13/16 x 4 5/16 x 1 in.) artefact (instruction booklet): 15.4 x 9.8 x 0.5 cm (6 1/16 x 3 7/8 x 3/16 in.)

DR1991:0021:001-002

- Calculator has a metal body and printed face plate with a plastic cover. It was received in a brown leather carrying case. The strap on the front of the case is detached on the left side. The instruction booklet is composed of 36 numbered folios, bound with two staples.

punched - on DR1991:0021:001, in the leather on c. of strap on front of case: "Fowler / CALCULATOR / MADE IN ENGLAND" imprinted - on DR1991:0021:002, in black ink, throughout, beginning on folio 1, u.c. to l.c.: " The / FOWLER / "12-10" / CALCULATOR / for / ARCHITECTS, BUILDERS, SURVEYORS, / TIMBER MERCHANTS, CRAFTSMEN, ETC. ... FOWLER'S (CALCULATORS) LIMITED ... Established 1898"; contents include instructions for using the scales and examples of calculations

• architecture

• case
• calculator