Experiments in psychical science, levitation, contact, and the direct voice
A 1919 study of psychical phenomena by the Belfast lecturer William Jackson Crawford, published in New York by E.P. Dutton for readers interested in spiritualism and séance research. Its pictures are simple line diagrams with lettered labels (M, R, T, A, B, K, S, D) showing the mechanics of a table, rod, and chair arrangement, which a designer could use as clean, schematic technical drawing reference.
