|Name and Model Number||Routledge’s rule|
|Country of Origin||UK|
|Date of Manufacture||c1860|
|Front Scales||Routledge engineering (Soho) scales: D = 1 - 10|
|Back Scales||Gauge points, conversion factors, circles, and pumping engine constants|
|Type of Rule||Other|
|Construction||Ivory & German silver|
|Area of Use||Other|
|Comment||A 2-foot, 4-fold rule used for Engineering.
This beautiful version of Joshua Routledge’s slide rule is in the more unusual 2-foot, 4-fold format,
and in ivory with German Silver furniture, not the most practical of combinations, but extremely attractive.
This one is not in the pink of condition, but is still a joy for any collector. It was made by Buck & Hickman
of Whitechapel Road, London; (c1820 – present day). The 6″ slide rule is perfectly usable and this model
includes a quite usable protractor which is accurate to 5º. Two-foot, 4-fold rules are very attractive, whether
in ivory and electrum or even in boxwoods and brass. Note that an equivalent ivory rule is about 30% heavier
than its boxwood equivalent.
|Donor||Collection of Peter Hopp|
|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.|