While researching for the Symbol Sourcebook, Henry Dreyfuss was reminded of an important set of symbols from earlier in the 20th century.

Without much thought or effort, I’ve been reading images inspired by Otto Neurath’s International Picture Language for most of my life.  No doubt you too have encountered derivatives of these informative symbols which can be found across the globe and online, from airport signage to The Noun Project.  Considered an early pioneer of infographics, Neurath...