This technical note offers comments and suggestions regarding four issues involved with the Frisch-Peierls memorandum of 1940: (1) Propagation of transcription errors in subsequent publishings of the memorandum; (2) Data bearing on F&P’s adoption of 10 b as the fission cross section of 235U; (3) The origin of their assertion that the critical radius is about 0.8 times the mean free path for fission if scattering is disregarded; and (4) The origin of a multiplicative factor of 0.2 in their yield formula and the consistency of their calculations.