Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to [William David] Dye Esq.; National Physical Laboratory, Teddington, Middlesex In answer to [William David] Dye's enquiry, informs him that there are no separate copies of his paper ['The valve maintained tuning fork as a precision time standard'] available, and that the only thing he can do is purchase copies of the whole No. 2 February 1925