Say in 1828. And here's a Merriam Webster definition from 1828:
THE'ORY, n. [L. theoria; Gr. to see or contemplate.]That number 4 item -- that IS scientific. Today? Don't think so, science has no way with genuine precision -- that mission is a poor stepsister to tenured and peer-pecked orthodoxy.1. Speculation; a doctrine or scheme of things, which terminates in speculation or contemplation, without a view to practice. It is here taken in an unfavorable sense, as implying something visionary.
2. An exposition of the general principles of any science; as the theory of music.
3. The science distinguished from the art; as the theory and practice of medicine.
4. The philosophical explanation of phenomena, either physical or moral; as Lavoisier's theory of combustion; Smith's theory of moral sentiments.
Theory is distinguished from hypothesis thus; a theory is founded on inferences drawn from principles which have been established on independent evidence; a hypothesis is a proposition assumed to account for certain phenomena, and has no other evidence of its truth, than that it affords a satisfactory explanation of those phenomena.
(Dear Coyoteman Field work is fun especially if one has a flask of good whiskey for the first breakfast's shot of liquid heat.)
Sorry, not for breakfast. We archaeologists take our work very seriously.
But on occasion, with the after-dinner coffee in a wilderness camp on a very cold night, a little cognac can be a fine thing!