ɐ sˈɪɹiz ʌv dɹˈʌmz ɔnðə dɪvˈaɪs wɜː sˈɛt ɐkˈoːɹdɪŋ tə ðə mətˈɪɹiəl bˌiːɪŋ kɹˈɔst ænd ɐ ɹˈændəm tʃˈɔɪs bᵻtwˌiːn fˈæst ænd slˈoʊ nˈuːtɹɑːnz.
A series of drums on the device were set according to the material being crossed and a random choice between fast and slow neutrons.