A link, and then a long digression (or several).
Andrew Robinson at the Oxford University Press blog writes about attempts at universal languages:
In the mid-1970s, with increasing international travel, the American Institute of Graphic Arts cooperated with the United States Department of Transportation to design a set of symbols for airports and other travel facilities that would be clear both to travellers in a hurry and those without a command of English. They invented 34 iconic symbols. The design committee made a significant observation: