Letter from H P Hollis, Royal Observatory, Greenwich, to [Robert William Frederick] Harrison 'My dear Harrison, Very many thanks for arranging the matter of presenting copies of the [Royal Society] memoirs to the Observatory magazine, and thanks to the Society for the decision. I at once take advantage of this to ask for a copy of Schuster memoir on Periodicity of sunspots. Sincerely yours, H P Hollis'. [4 August 1906]