Full Details

Name and Model Number Wilkinsonís rule
Country of Origin UK
Date of Manufacture c1877
Front Scales Routledge variant, D = 1 - 10
Back Scales Gauge points, conversion factors, circles and pumping engine constants
Scale Length 11Ē
Type of Rule Other
Construction Boxwood & brass
Area of Use Other
Comment A 2-foot, 2-fold rule used for engineering.
Wilkinsonís rule is basically a Routledge slide rule with a few "improvements",
namely a Log scale which allows the mantissa of the logarithm to be ascertained
across two legs of the rule. Also it has additional scales compared to its parent,
the Routledge engineers rule. Nothing is known about T. Wilkinson, other than that
he was an engineer who worked in the Midlands in the late 19th century.
Rarity RR
Donor Collection of an English gentleman.
Match Number 62

RR = Rare -- 1 of 25 collectors has one; it may take a year to find an example in the marketplace.   
RRR = Very rare -- only very few known to collectors; may take several years before one comes up for sale.   
RRRR = Extremely rare -- a museum piece; unlikely that an example will ever come up for sale.