Slide rules manufactured in Hungary
Gamma, Logar
The best known hungarian slide rule is the 10-inch Gamma type 2512.
After the World War II, in the end of 1940s the changed politics in the country decided to import required goods from other socialist
countries - due to restricted amount of foreign currency available, but the big factories produced slide rules were in imperialists' territory.
So Hungary had to built slide rule production line at the Gamma factory in Budapest. They started manufacturing
in 1949, but later the plant was moved to Vác, and in 1957 to Monor, where the Brush Factory produced rules for the
end of the 1970s.
You can read further details on Gamma and Logar slide rules on the page
Brief history of "Gamma" slide rules.
Calderoni, ITG
The small grocery shop on Váci St. founded in 1819 became later an optician store, then from 1872 started to
distribute and produce teaching accessories. The company made much more profit year by year, the optician apprentice
Ferenc Hopp who became a partner in the Calderoni Plc, could sponsor his collecting journeys around the world, and
he is best known for his famous east-asian collection and museum demonstrating that.
In the 1920s, after introducing the use of slide rules at secondary schools, they started production wooden rules.
The best known model was the Calderoni-Sebők type business rule. The company and subsidiaries was nationalized in 1948,
and renamed to Iskolai Taneszközök Gyára (Factory for School Demonstration Tools) in 1951. They were still produced
slide rules for schools for years. In 1968 national companies that have similar profiles were merged to TANÉRT.
You can read further details on Calderoni and ITG slide rules on the site
Slide rules manufactured by Calderoni later ITG.
Juszt László and Gyula
Near to the National Museum of Budapest, once were an optician store. In the beginning, two opticians - László and Gyula Juszt became
distributor of big western factories (A. W. Faber, later Faber-Castell; Albert Nestler, Dennert & Pape) and publishing
books on how to use these instruments, but later
produced cheaper versions of the standard slide rules under the name GENIE. These rules were made of cheaper wood with simpler or missing
steel springs and reinforcing, the scales were printed on paper pieces which have been polished before glued on.
You can read further details on site
The Juszt slide rules and books.
Telefongyár (Factory of telephones)
There were a very interesting hungarian circular slide rule named Rotor which have been produced by Telefongyár (Factory of telephones)
from 1933 to 1938 under their own patent. This is two new silver (German silver) discs - a bigger outer and a smaller inner -
connected together with an index, and has logarithmic scales on the front and trigonometric precision scales on the back.
The production has been abandoned due to increased military needs.
More on this on page
The ROTOR circular slide rule.
Károly Kökény
In the fifties there were a cheap "exercising slide rule" made by a secondary school teacher Károly Kökény from Miskolc.
These rules were made of cardboard and celluloid. Details on this are in the page
Exercising slide rule made by Károly Kökény.
József Kálmán
From 1942 produced special slide rules for machining made of aluminium at the Ganz factory. The rules which was planned by
József Kálmán later made of paper due to metal using restrictions. Kálmán published a book titled "A gazdaságos forgácsolás számítóábrái"
(Economic metal cutting nomograms) in 1965 with description of his inventions.
Details coming soon!.