Full Details

Name and Model Number Boucher Model 0?
Country of Origin France?
Date of Manufacture ~1876?
Front Scales Tan,C,√√ (Square root – 2 circles)
Back Scales L, 3√3√3√ (cube root – 3 circles)
Scale Length Approx 12cm.
Type of Rule Rule
Construction Metal, porcelain dials
Area of Use Generic
Comment Unknown maker, the side winder makes this a ‘Boucher’ calculator,
should this have been a push-clutch, we could all it a ‘Calculigraphe’.
The scales are typically better known as Calculigraphe scales.
Only two examples are known and further information is urgently sought.
This might be the very first Boucher design.
Illustrations courtesy of the Gemmary.
Rarity RRRR
Donor Collection of Peter Hopp
Match Number 45

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.