Diagrams, geometrical diagrams and spectra by Joseph Norman Lockyer 15 plates, five of which show geometrical figures relating to nebulae, while ten show various chemical spectra of 'heavenly bodies'. Subject: Astronomy / Spectroscopy Prints of these diagrams were published in volume 44 of the Proceedings of the Royal Society alongside the paper 'The Bakerian lecture.—Suggestions on the classification of the various species of heavenly bodies'. April 1888