It was also during 1939, in another part of the Frankfurt conglomeration, that a specialist foundry was opened. The specialist foundry at Frankfurt-Bonames applied a centrifugal casting process to produce and ribbed cylinders suitable for use in air-cooled motors and compressors, turbine and bearing housings for turbochargers, and other more rarefied applications. It was also during 1939, in September, under the terms of a recently concluded secret agreement between Berlin and Moscow, that Poland was invaded by the German army from the west and, slightly more than two weeks later, by the Soviet army from the south and east. Another world war had been launched in Europe.