Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to S. B. Gaythorpe Esquire; 3 Prospect Road, Barrow-in-Furness Writes again to Mr. S. B. Gaythorpe on on the subject of the [John] Wallis, Horrocks and [Christian] Huygens. Confirms that the 'Letter Book' cited by [Thomas?] Birch is the volume of the transcribed series, however, the original letter is in the Wallis Letters, Volume I, Number 14. With regards to the Huyghens visit, though there is no specific mention in it in their Journal Book, notes that it is plain that he visited London sometime in 1661. 20 April 1921