Paper, 'On an effect of light upon magnetism' by Shelford Bidwell Bidwell writes: 'Several experimenters in the early part of the present century tried to magnetise iron and steel by the action of light, but I do not know of any recent attempts in this direction, and of late years the thing has been generally regarded as impossible.' Annotations in pencil and ink. Subject: Optics Received 11 March 1889. Read 21 March 1889. A version of this paper was published in volume 45 of the Proceedings of the Royal Society as 'On an effect of light upon magnetism'. 1889