|Name and Model Number||Coggeshall Type |
Carpenter’s Slide Rule
|Country of Origin||England|
|Date of Manufacture||Probably first half of 19th century|
|Front Scales||3 two-cycle logarithmic scales running from 1 to 100 above and on the slide, and a 4–40 “Girt line” scale below the slide.|
|Back Scales||24 inch linear scale|
|Scale Length||9 inches|
|Type of Rule||Other|
|Construction||Boxwood, with 2 brass hinges and a wooden slide with 2 brass buttons.|
|Area of Use||Other|
|Comment||Made by W. Ransley of Stangate, London, for carpentry calculation and measurement.
A lovely 3-fold, 2 foot variation of the Coggeshall design. Both the form factor and the maker are quite rare.
Peter Hopp’s book on joint slide rules calls this form factor “amongst the nicest and rarest of joint rule”.
For more photos and info see http://www.nzeldes.com/HOC/JointRules.htm
Also see the donor's article on this rule in the Journal of the Oughtred Society, Vol. 20, No. 2, Fall 2011.
|Donor||Collection of Nathan Zeldes, Israel|
(Click Picture for Details)
|In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen|
|(1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD.|
|• RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace.|
|• RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale.|
|• RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale.|