Full Details

Name and Model Number Post 1466 Ritow Manifold
Slide Rule
Country of Origin Made in Germany for Frederick Post Co. of Chicago
Date of Manufacture 1925 -1931
Front Scales 1st half A [2nd half B inverted 1st half B inverted] 2nd half A
Back Scales Back of slide: C & K --- Back of rule: Constants
Scale Length 1 m (two 50 cm scales folded)
Type of Rule Slide Rule
Construction Closed-frame mahogany with celluloid laminate scale surfaces. 52.8 cm x 3.6 cm. Frameless cursor marked Germany. Slide friction-adjusting mechanism like that of Dennert & Pape.
Area of Use Generic
Comment Both "Made in Germany" & "Frederick Post Co." engraved in well beneath slide. Maker most likely Dennert & Pape.
Very unique extended scale arrangement of half & inverted scales to achieve a 1-meter long scale on a 50-cm slide rule.
Scale arrangement patented by Herman Ritow for Frederick Post Co.
Rarity RRRR
Donor Collection of Ed Chamberlain
Match Number 175
(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.