Full Details

Name and Model Number Fischer Calculigraphe
Country of Origin Switzerland
Date of Manufacture 1972
Front Scales  
Back Scales  
Scale Length  
Type of Rule Watch Type
Construction Steel Case
Area of Use Generic
Rarity RRR
Donor Collection of Colin Barnes
Match Number 80

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.