Sergey
== Description == '''Fig. 2: velocity–time rectangle ABCD with diagonal''', from '''''The Spiritualist'', vol. XII, no. 21 (whole no. 300), 24 May 1878, printed p. 250''' (PDF page '''12 of 16'''). Part of Desmond G. Fitzgerald's article ''The “Conservation of Energy” in Relation to Certain Views of the Theosophists'', beginning on printed p. 249. The author is credited for the article, not assigned as illustrator or engraver. Matches '''item 3''' on HPB-SB-7-136. Rectangle vertices A/B/...
