*1) The model J comptometer was introduced in 1926 and was easily distinguished from its predecessors by its green key tops. Click here to see a film clip courtesy of The Institute for Mathmatics and Computer Science at Ludwigsburg, Germany,

*2) A portable, full keyboard, direct key-driven machine, designed for high-speed calculations involving all branches of mathematics. It is duplex in operation, in that it will add in more than one column at a time, each column having the capacity to add, receive and carry simultaneously.


Content without guarantee! (UK); Inhalt Ohne Gewähr! (DL)

Type name / number: Adding Machine, Comptometer - model J
Production / SN: J314579 *1)
Calculating principle: Rocking Segment / Direct adding (key driven)
Calculating functions: Add, Subtract with nine complement
Input accuracy 10 digits
Calculating accuracy: 11 digits
Extra's: Display of input- and total / result number
Designer: Mr. E. Felt
Production year: 1926 - 1930
Case material: Copper plated metal. Bottom RVS.
Weight: 9,2 Kg
External links:  
Previous owner: Luigi Serrapiglio, Lehrte / Sieverhausen, germany
Cosmetic imperfections:
(I accuse no one)
one green key top 6, and the red extra key (function ?) are missing.
Date of receiving: 2010 - july
Machine story: Fully functional on arrival. Only cosmetic cleaning. Probably not opened before, relatively clean inside.