Quiet Street Antiques of Bath has dated this piece to the 1800s.
The cistern cover is original and of solid mahogany.

The door opens to reveal the good engraved and silvered register plate, signed by the maker, and the thermometer is original with "cricket ball" reservoir. Perfect working order and guaranteed at least two years.

Dominick MANTICHA was a barometer maker of repute, known to have been working in London around 1805 and there is a barometer by him in the Science Museum. In "English Barometers" by Goodison, there is a chapter devoted to him and his work; see pages 176/178.
Quiet Street Antiques of Bath has dated this piece to the 1800s.
Fine antiques at sensible prices
You can view the stock and full dealer information on the Quiet Street Antiques of Bath Profile Page