Copy letter from Robert William Frederick Harrison, to Sir William [Macewen], [Fellow of the Royal Society] Adds a few lines to the official note to express the hope, which several Fellows have expressed to him, that Macewen would be willing to add to the great value and interest of his paper by pointing out the significance, scientific and practical, of his very suggestive experiments. Queries if Macewen could be persuaded to do this and if so Harrison will return the manuscript. 29 June 1906