– Unlike the very early calculators by Schickard, Leibniz, Pascal, Grillet, and others, Fardoil's calculator was a true 'pocket calculator' as it is flat and would fit in any pocket. This simple use of a planetary gear enabled Fardoil to provide a read-out in the range of 0–100 without the need of a carry-over from 9 to 10, 20, 30, etc. The two scales show the numbers from 0–9 for additions and for subtractions respectively. Fardoil achieved this improvement by utilizing a planetary gear turning two round scales underneath two stationary hands ten times over the entire range of the calculator. – Fardoil's contribution to the development of mechanical calculating devices is the introduction of his mechanism which enables the operator to read the result without counting the dividing marks on a circular scale of a disc shaped adding machine. Traces of silver indicate that this fine instrument was originally silver-plated. The machine - signed 'Pierre Fardoil à Paris - is hand-crafted in steel and brass, measures 5-1/2 inches in height and is in perfect working condition. Very early machine for adding and subtracting numbers from 0-100 in the shape of an astrolabe. – Noch nie auf einer unserer Auktionen in 30 Jahren angeboten! – Eine Riesen-Rarität! – Äußerst seltenes Sammlungsstück, da nur in Kleinstmenge produziert. Ohne Einstellstift, mit 2 Schrauben an Deckplatte, blockiert. Volle Zehner-Übertragung, Nullstellung durch Herausziehen der linken Zahnstange. Roth'sche Rechenmaschine mit Direktanzeige', 1841įrühe 8-Scheiben-Addiermaschine in Linealform von Dr. – The only example offered in our 30 years of Specialty Auctions! – A giant rarity!

– Extremely rare collector's item, produced in small numbers for a short time only.

No set stick, only 2 screws on brass front plate, blocked. Setting to zero by pull-out of left feed-rack.

Roth Calculator with Direct Display, 1841Įarly 8-disc adding machine in ruler-form by Dr.

E leitz wetzlar milliamperes