* Translation by Andries de Man

I) The Payen models: 1887-1907

If one knows that Payen was Thomas de Bojano's constructor since the early 1870's, one can imagine that there was no complete change of ideas!
After the decease of Thomas de Bojano, in 1881, the construction of the arithmometer continued, maybe under management of one of his sons. Until 1887, the machines are always marked "Thomas de Colmar, 44 rue de Châteaudun, Paris" ! But they had already been constructed by Payen for a long time !
In the end, he put his own label on the machines, maybe after the cessation of rights. (this is still subject to research).
The first model Payen P1 is identical to the last models of Thomas. Some improvements were made in models P2 and P3, but regarding the tens-carry mechanism, nothing had changed! Why change a winning team ?
The only notable difference is the replacement of the square block by a long triangular tooth mounted under the dial.
But its function is identical.

New tooth in Payen P3 / P4 (1895-1907)	Square block (1856-1895)