Copy letter from an unknown correspondent, to Messrs Richard Frères, 43 london Wall, E.C. With reference to the schedule of exhibits completed by Frères, they accept all the instruments for exhibit, with the exception of those exhibited before: the universal electric chronograph, the self-recording barometer, and the self-recording hygrometer. Also asks that they be informed what current will be required for the apparatus. 17 April 1891