I like to imagine that thermodynamics happened because industrial metallurgy and boiler design advanced to the point where people started asking "what are the fundamental constraints?"

There's a chance that it didn't actually happen that way, though.

edit: I also heard that Louis Pasteur did work for breweries, answering the question "Why do some batches come out nasty while most are fine, given the same inputs?"

The history of steam engines would suggest that our understanding of thermodynamics developed out of a large base of first-hand experience. Same story for Calculus. And the t-statistic was developed by a QA guy (student) at Guinness.