Paper, 'Note on the spectrum of the nebula of orion' by J [Joseph] Norman Lockyer Lockyer writes: 'In a former communication I gave in detail observations made by means of a siderostat, which seemed to put beyond all reasonable doubt the question of the origin and true wave-length of the chief nebula line. Although, as I stated in the communication referred to, I regard this question as one of secondary importance, I have commenced another series of investigations with a view of eliminating all possible instrumental errors. The new method has not been completely carried out, but a sufficient approximation to it has been reached to render the results obtained of some interest.' Annotations in pencil and ink. Note on front reads 'Copy 14/2/90'. Subject: Astronomy / Spectroscopy Received and read 13 February 1890. A version of this paper was published in volume 48 of the Proceedings of the Royal Society as 'Note on the spectrum of the nebula of orion'. 1890