Copy letter from Herbert Rix, to Lord William George Armstrong, Fellow of the Royal Society The lecture room will be at Armstrong's disposal for a portion of the evening on 10th May and the Society has its own electric lantern which is at Armstrong's service if required. Rix is half afraid however that this will not do for Armstrong's experiments, as the Society has no horizontal stage and the lantern is only suitable for showing ordinary photographic slides in a carrier of the usual dimensions. If Armstrong could bring his own electric lantern the exhibit would doubtless be more successful. 12 April 1893