To Picture Show – a short piece, called I think, The Romance of Gears, [“Mechanical Principles” by Ralph Steiner] consisting of close-up enlarged pictures of all manner of gears in action – very beautifully photographed – At the last, with trick photography they showed some of the foregoing shots multiplied and overlapping; the effect was thrilling, like music.
Charles E. Burchfield, Journals, September 14, 1934