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Washington circa 1924. "Bureau of Standards." National Photo Company Collection glass negative, Library of Congress. View full size.
I am going to venture a guess that this man is testing various aggregate/asphalt mixtures for road use.
I like how he has tied his tie extra short to keep it away from possibly flames.
Just missing the Tesla coils and the Frankenstein monster!
"Next mix in the chopped pecans and walnuts, add the candied cherries, raisins, citron and cinnamon...mix all together, pour into greased loaf pans and bake two hours at 325 degrees."