A Daily History of Holes, Dots, Lines, Science, History, Math, Physics, Art, the Unintentional Absurd, Architecture, Maps, Data Visualization, Blank and Missing Things, and so on. |1.6 million words, 7500 images, 4.9 million hits| Press & appearances in The Times, Le Figaro, Mensa, The Economist, The Guardian, Discovery News, Slate, Le Monde, Sci American Blogs, Le Pont, and many othr places… 5000+ total posts since 2008.
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JF Ptak Science Books Quick Post 
I just found this in the October, 1930 issue of Popular Mechanics and like all of these sorts of identifiers it struck me as potentially useful. At the very least, it is interesting, and so I pass it along:
Larger images of the silhouettes below: