Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Sir Joseph [Ernest] Petavel, FRS Refers to the paper by [David William] Dye, 'Calculation of a primary standard of mutual inductance of the Campbell type', that Sir Joseph [Ernest] Petavel recently communicated to the Society. Explains that it has been recommended for printing in the 'Proceedings', however, that the referee suggested more detail be given on the Campbell form of standard. Asks Sir Petavel to enquire whether the author wishes to make this change before the paper is sent to the printers. 23 February 1922