An Interesting Signed Letter From Otto Of Greece To Didier Roth About His Calculating Machine, 1843

An Interesting Signed Letter From Otto Of Greece To Didier Roth About His Calculating Machine, 1843

950 euros

Categories: Bookshop, Scientific, Scientific Books, Calculating


A very rare manuscript document about the promotion of Roth’s pioneering calculating machine, the direct descendant of Pascal’s machine.

Indeed, Roth’s adder machine is based on the same principle as that of Pascal’s machine but is more efficient : it is a rectilinear machine with a zeroing mechanism using a tens carry mechanism.

 In the present signed letter, Otto, the first modern King of Greece elected in 1832, is thanking “Docteur Roth” for offering him one of his calculating machines.

 “J’ai reçu avec plaisir l’additionneur automate que vous m’avez envoyé et je vous félicite de l’invention d’un instrument aussi ingénieux qu’utile”. [“I was pleased to receive the automaton adder you sent me and I congratulate you on the invention of such an ingenious and useful instrument”].

 He adds : “Cette invention vous fait d’autant plus d’honneur qu’elle nous offre la solution satisfaisante d’un problème auquel se sont essayés depuis si longtemps des esprits distingués”. [“This invention gives you all the more credit that it offers us a satisfactory solution to a problem that distinguished minds have been trying to solve for such a long time”].


Roth applied for several patents for calculating machines between 1840 and 1844 and his adder encountered a brief commercial success. Unlike Thomas de Colmar’s arithmometers, we ignore to which important people Roth sent his calculating machine for promoting it.

Therefore, this official letter provides rare and important information about the early commercialization of calculating machines in Europe.



Otto of Greece, signed Letter, 4 May 1843 ; 1 page 4to with envelope to Docteur Roth in Paris.

Some scarification on the envelope and letter without loss or damage.

The letter and envelope are preserved in a large 19th-century folder with a manuscript inscription indicating that they were given by “Julie[/a] Roth”, probably the wife or daughter of Didier Roth.

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FR Le Zograscope

Established by Alexandre Piffault in 2014 and based in Paris at 5 rue de Condé, 75006, very close to Odéon, Le Zograscope specializes in antique and rare books in Science, Medicine and Technology, and rare antique instruments in the same fields. We have especially a strong interest in early and continental microscopy, early and special mathematical/drawing instruments, medical and surgical instrument, and rare technology.

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