An old passion rekindled
These later years of Armstrong's life saw his love-affair with electricity re-surface. He reprised his earlier lectures on electricity when he delivered a lecture and demonstration to the Lit & Phil, to mark its centenary in February 1893, on the novel effects of the electric discharge. During the lecture he made reference to his thirty-year tenure of the Presidency of the Society and recalled his demonstration of his hydroelectric machine forty-nine years earlier. In this letter from Armstrong to Robert Spence Watson, written the previous month, Armstrong is seemingly gathering facts for inclusion in the lecture:
I dare say that from your knowledge of the history of the Lit & Phil you can readily tell me what was the date of my lecture to the Society on the electricity of steam & also the date of the lecture at which I exhibited a model of the hydraulic crane. Please also tell me at which date I was first elected President of the Society. 17
Further experimentation with electricity led to Armstrong's publication of the volume Electric Movement in Air and Water, containing a set of striking photographic images of electric discharges taken by the Rothbury-based photographer and friend of Armstrong John Worsnop.
