The FERMIAC used this method to create two-dimensional neutron genealogies on a scale diagram of a nuclear device. A series of drums on the device were set according to the material being crossed and a random choice between fast and slow neutrons.
The FERMIAC generated two-dimensional neutron genealogies on a scale diagram of a nuclear device by employing this method. The device had several drums, which were set according to the material involved and randomly chosen between fast and slow neutrons.