Thanks for your responses Ruskie and ShaunJ: Those maps are awesome! I like how old maps are side-by-side arial photos. Yes, I have Googled for information but haven't found much. Perhaps I'm not using the correct search terms.
I am a descendant of William Bate. I know that several generations of Bates lived at Trennick in the late 1700-early 1800s. I think he may have owned Boscawen Park as well. He owned Trennick Mill, and was landlord at the Blue Anchor Pub by 1777 at least. His son Charles took over Trennick then sold it in 1821 - or at least it was up for sale in 1821. I don't know who bought it.
Henry Newell Bate, maltster, took over Bate & Conn, I think. He moved to Canada in 1833. He and Henry Conn, who'd remarried a few months earlier, dissolved the business in July 1833.
The information I have is like a few pieces of a puzzle. I was hoping to find a history of Trennick and the brewery. I've seen it written that the Blue Anchor Pub is the oldest in Britain and wonder how long Bates owned it. We've traced the family back to the 1500s in Blisland, Cornwall.