WATANABE, Masahiro

Bituminous coal

[Abstract] This essay revisits the history of the Rosin–Rammler–Sperling law of particle size distribution. The original equation R = exp(−bxn) first appeared in April 1932 in a research paper by Rosin, Rammler and Intelman. The distribution law expressed by the exponential formula and plotting log log 1/R against log x was officially proposed in June 1933 by Rosin, Rammler and Sperling in Report C 52 of the National Coal Council, Germany, not readily available in Japan. However, in December 1933, they published a brief version and Bennett presented a diagram specially scaled for the log-log-reciprocal plot in Britain.