Paper, 'Preliminary note: The numerical registration of colour' by [William De Wiveleslie] Abney Manuscript followed by printed proof. Abney writes: 'The Committee of the Royal Society on Colour Vision having put into my hands the determination of the colour of certain signal glasses, a memorandum was drawn up on the method of the numerical registration of colours and submitted to them.' Annotations in pencil and ink throughout. Subject: Chemistry Received 6 February 1891. Read 19 February 1891. A version of this paper was published in volume 49 of the Proceedings of the Royal Society as 'The numerical registration of colour. Preliminary note'. 1891