In reply (letter of November 19, 1927), MacMahon expresses the view that Redfield has made a valuable contribution to the subject and goes on to mention a conjecture which he himself made in his recently delivered Rouse-Ball memorial lecture.
In response (letter dated November 19, 1927), MacMahon acknowledges the value of Redfield's contributions and then mentions a conjecture that he himself presented in his recent Rouse-Ball memorial lecture.