Letter from William Gosset to Sir R A Fisher On the calculation of the probabilities for "Student"'s T test (Metron 1925 "New Tables for Testing the Significance of Observations" for which Fisher supplied an asymptotic formula similar to that shown in Ann Eugenics (11:141-172 "The Asymptotic Approach to Behren's Integral" with prospect of Guinness' sending Mr Somerfield to work in the Statistical Department at Rothamsted. 7/11/1922