Letter to Eric Keightley Rideal, regarding two papers 'On the catalytic cyclization of aliphatic hydrocarbons. I' and 'On the catalytic cyclization of aliphatic hydrocarbons. II' by E F G Herington and Eric Keightley Rideal Sectional Committee: Physics Encloses two copies of the proof, which has only been printed for confidential circulation, as publication has been withheld until after the war. The proofs must be returned to the Royal Society once corrected. One copy each will be sent to the authors. Requests suggestions for government departments which might be interested in receiving copies. [Published in the 'Proceedings of the Royal Society of London'] No received date. 20 January 1942