Slide rule, circular, Blackwell Average Speed Calculator, single-sided, two concentric plastic disks (white), the top one having a pointer (printed in red) attached, rotatable. No separate cursor. With labelled plastic sleeve and instruction booklet.
Also included in the package are a Garford Romer and a booklet. The Garford Romer is a square navigational map grid reference finding aid, it comes with instruction leaflet. The booklet titled Rally Navigation by L.N. Needham (1963), has a list on the inside front cover of other items sold by the publisher Rally Equipment Ltd including the Blackwell calculator.
They all housed in a plastic bag.
Model name, manufacturer, and patent number on slide rule, on top disk, in center, printed in black ' Blackwell Calculator / Made in England / British Patent No.707740 ', on back of lower disk, in lower center ' Obtainable from: / Blackwell's Metallurgical Works Ltd. / (Calculator Department) / Thermetal House, Garston, Liverpool. '. White paper label on back of lower disk, in upper center, handwritten in black ' Bromley / 1983-1 '.
Name on plastic sleeve, printed in red ' Blackwell Average Speed Calculator '.
Title and manufacturer on instruction booklet, printed in black ' Blackwell Average Speed Calculator / Mark 1 / Instructions / Blackwell's Metallurgical Works Ltd. / Thermetal House, Garston, Liverpool 19 '
Logo on Garford Romer, in upper left, printed in black ' Garford Romer / Reg.d Design '.
Title on instruction leaflet, printed in black ' Notes / on the use of / The Garford Romer / ( Regd. Design No. 872947) '.
Title and publisher on booklet, printed in black ' Rally Navigation / by / L.N. Needham / Published by / Rally Equipment Ltd., 295 Edgware Road, Colindale, N. W. 9 '. Manufacturer and notes on back cover, in center ' Printed by / J. B. Shears & Sons Ltd. / 191 New King's Road, London - S.W.6. ', in lower right ' Reproduced from the Ordnance Survey Map with the sanctions of the Controller of H.M. Stationery Office Crown Copyright reserved '.