British Slide Rule Co. Technical Standard

(25cm Scale, Log Log)

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British Slide Rule Co. Technical Standard
Image Summary
System: Log Log
Specialization: -
Type: Closed frame
Material: Mahogany
Facings: Celluloid/Paper
Scale Length: 25cm No of Scales: 9
Front Length: 302mm Front Width: 35mm
Language: English Origin: British
Date: c1944-??
Features/Notes: Made by the British Slide Rule Co. but this brand does not appear on the slide rule itself.
Scales (colours as shown)
Front: LL2, A [ B, C ] D, LL3 Back: [ S, ST, T ]
Labels Left: M, A [ B, C ] D, N Labels Left: [ S, S. T. , T ]
Labels Right: - Labels Right: [ S, S. T. , T ]
Style: Railway track Typeface: Sans-serif
Extensions: A, B, C & D beyond 1 & 10 Decimals: As units between 1 & 2 on C & D
Gauge Marks: p (3.14) on A, B, C & D
A (p/4=0.785) twice each on A & B
M (1/p=0.318) on A & B
C (1.13) on C & D
C1 (3.57) on C & D
L (2.303) on C
Rulers: inch on top edge
cm on bottom edge
Features/Notes: Printed on paper with clear celluloid facing.
Stock: Upper and lower rails joined with sprung steel and plastic facing in the well.
The back features two plastic frames, one at each end, each secured with 4 screws, one in each corner. The frames each have a finger recess on the outside edge and longditudal flex grooves. Each frame encloses one hairline for reading the scales on the reverse of the slide.
Between the frames is a wooden filler strip, split londitudinaly, covered by paper tables and a plastic facing, rebated into the stock rails.
Front, well, top and bottom edges and back celluloid faced.
Facings on front and edges are secured with metal pins.
High cursor grooves.
Bevelled top and bottom edges.
Length x Width x Height (mm) - 302 x 41 x 14
Slide: Double sided.
Celluliod faced on both sides.
Facings are secured with metal pins.
Front face width (mm) - 13
Cursor: Plastic pane fixed to separate top and bottom plastic runners with 4 pins, one in each corner.
Single central black hairline.
Left end riveted steel spring on top runner.
Width x Height (mm) - 32 x 44
Printing (colours as shown)
Stock: -
Slide: "THE TECHNICAL STANDARD SLIDE RULE" at the left end, stradling the fixing pin.
"BRITISH MADE" at the right end, stradling the fixing pin.
Cursor: -
Labels: On back, paper table featuring mathematical and physical constants and formulae.
Box (colours as shown)
Style: Square L x W x D mm: 308 x 58 x 25
Material: Cardboard Colour: Maroon
Construction: 2 part, internal sleeve join.
Originally faced, now heavily covered with tape.
Printing: None seen.
Labels: None seen.
Detail Images
Click on the images for enlargements.
Click on the images for enlargements.
Click on the images for enlargements.
Count Belmiro © Copyright December 2011 - July 2015
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