Referee's report by Arthur Stanley Eddington, on a paper 'The theory of the inertial field' by Alfred North Whitehead Sectional Committee: Mathematics Recommended for publication in the 'Proceedings of the Royal Society of London'. The paper continues from the author's previous one, in giving reasoned statements for the experimental results. It is important the paper is printed, in order that the theory can be understood or criticised. [Not published] Endorsed on verso as received 17 October 1921. [October 1921]