P A Oxley Antique Clocks & Barometers has dated this piece to the 1800s.
The silvered brass scale is calibrated from 28" to 31" and features a slivered brass vernier for recording and measuring the air pressure and an integral thermometer which is calibrated from -10º to 120º Fahrenheit. The dial is also engraved with typical weather indications and the makers name and place of work. The dial is accessed through a lockable glazed door.
The base of the barometer also features a brass cistern screw for transportation.

A beautiful example.
Note: The Dollonds were prolific and excellent instrument makers. We can determine from its style that this barometer is by George Dollond. Like his famous Uncle Peter Dollond, he was also instrument maker to the Royal Family and was one of sixteen instrument makers who exhibited at the Great Exhibition, Crystal Palace in 1851.
P A Oxley Antique Clocks & Barometers has dated this piece to the 1800s.
You can view the stock and full dealer information on the P A Oxley Antique Clocks & Barometers Profile Page
P A Oxley Antique Clocks & Barometers is a registered member of LAPADA