The Bolyai calculator is a late, quite rough and ready Odhner clone, built by the Electromures firm in Tirgu-Mures or Târgu Mureș, Romania.

The quality leaves something to be desired, which is obvious from the lack of quality in the casting (they used something like Rhine sand as casting sand, I think) and the antiquated design without tens' carry in the revolution counter, which is quite a disadvantage in 1963, which is when this machine was built.

It was named after János Bolyai, a Romanian mathematician who only ever published 24 pages of work on non-Euclidian geometry in his early career, but continued his work in private, and generated about 20.000 pages of mathematical notes by the time of his death. The university in Cluj-Napoca was named after him, and probably the 100th anniversary of his death also prompted Electromures to name their calculator after him. The font is somewhat reminiscent of a lightning bolt, which makes it somewhat hard to read, and plenty of "interesting" names are given to this machine.

Some pictures, also showing the casting quality, serial number and build year. I had to replace one of the clearing cranks, and the machine is a bit stiff in operation probably from someone lubricating the pinwheel cylinder at some point. Also, the top of the tabulator is made in plastic - I have no idea if this is an original feature or a later repair.

Bolyai picture 1

Bolyai picture 2

Bolyai picture 3

Bolyai picture 4

Bolyai picture 5

Bolyai picture 6

Bolyai picture 7