Conversation so far:
what happened inJames Watt's later years?
James Watt retired in 1800.
Why did James Watt retire in 1800?
It was the same year that James Watt's fundamental patent and partnership with Boulton expired.
What else did James Watt do after he retired when his fundamental patent and partnership with Boulton expired?
James Watt continued to invent other things before and during his semi-retirement.
Did James Watt travel anymore after he retired?
James Watt and his wife travelled to France and Germany, and he purchased an estate in mid-Wales at Doldowlod House, one mile south of Llanwrthwl, which he much improved.
Did James Watt accomplish anything after retirement?
James Watt proposed a method for constructing a flexible pipe to be used for pumping water under the Clyde at Glasgow.
Did James Watt's proposal for a method for constructing a flexible pipe to be used for pumping water under the Clyde at Glasgow pull through?
Is there anything else interesting about James Watt aside from his proposed method for constructing a flexible pipe to be used for pumping water under the Clyde at Glasgow?
In 1816 James Watt took a trip on the paddle-steamer Comet, a product of his inventions, to revisit his home town of Greenock.
Did James Watt ever win any awards for his inventions?

Question: Did he invent anything else?
Self-contained rewrite: Did James Watt invent anything else after retiring in 1800?