Thomas de Colmar, Paris c1875


A large French arithmometer with 10 entry digits, 11 revolution counter digits and 20 product digits (ie a 10-11-20 machine), stamped Thomas de Colmar A Paris inventeur No. 1300.

The item is sold with a copy of a booklet for a similar machine which explains its use.

The arithmometer is built to Thomas de Colmar’s 1865 patent and the serial number 1300 dates the machine to circa 1875.

Charles-Xavier Thomas de Colmar (1785 - 1870) registered his first arithmometer patent in 1820 but it was not until the 1850’s that the mechanical problems were solved giving a machine which could be used reliably by industry and commerce. After Charles-Xavier’s death in 1870 manufacture was continued by his son and grandson until 1887 when the business was sold to Louis Payen who continued manufacture under his own name.

The Thomas de Colmar arithmometer was the world's first successful and widely used mechanical calculator.


Here you can see the left hand side of the calculator and below is shown the right hand side.


The calculator retains much of its original lacquer and is in working order.

The calculator is housed in its original ebonised box with brass stringing, the lid inlaid with brass letters reading Arithmométre.
Box size 28 x 7½ x 4 inches.



Stock No. C1117

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