I got to meet James Joule in the lobby at Manchester Town Hall. He was a local brewer who did an experiment where falling weights pulled a paddle wheel in a vat to do mechanical work on the liquid. The temperature of the liquid was raised and thus the First Law of Themrodynamics had its beginnings. I am finding it hard to get used to the convention that it is capital J for the abbreviation as in 100J and small j for the full name as in 100 joules.