Full Details

Name and Model Number Billeter, Ernst Blitzrechner
Country of Origin Switzerland
Date of Manufacture c. 1905
Front Scales Circular C & D scales
Back Scales none
Scale Length 4 m
Type of Rule Disc
Construction 12.4-cm dia.; varnished paper scales on hard board disks; nested disk type; metal ring at outside edge; turning knob for inner disk on the back.
Area of Use Generic
Comment Ernst Billeter was a brother of Julius Billeter.
Rarity RRRR
Donor Collection of Ed Chamberlain
Match Number 277
(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.