Referee's report by John William Nicholson, on two papers 'The physical meaning of spherical aberration' by L C Martin and 'Eddy-current losses in cylindrical conductors, with special applications to the alternating current resistances of short coils' by S Butterworth Sectional Committee: Mathematics Recommended for publication in the 'Proceedings of the Royal Society of London'. Finds the paper excellent, but will only be confident once it has been seen by Arthur Schuster, who is suggested as a second referee. Suggests the paper be corrected for spelling and references. Refers to work by Rayleigh [?]. [Not published] Will return the paper by S Butterworth with a favourable report [RR/26/25]. [Published in the Philosophical Transactions of the Royal Society A, 1922] No received date. 4 June 1921