Lot 6142
Mrs Janet Taylor, 104 Minories, London, England - Victorian mahogany cased Sympiesometer c 1860, gl...
Mrs Janet Taylor, 104 Minories, London, England - Victorian mahogany cased Sympiesometer c 1860, glazed mahogany case with a cavetto moulded pediment, rectangular silvered register and Fahrenheit temperature scale, hydrogen gas filled syphon tube and a separate sliding vernier calibrated in barometric inches, to the left a separate mercury filled Fahrenheit thermometer and makers signature beneath, circular rotating recording disc within a curved aperture.
Mrs Janet Taylor is recorded as a barometer retailer and navigation teacher in London, England, 1845-1875.
The Sympiesometer patented in 1818 by the Edinburgh barometer maker Alexander Adie was an improved version of Robert Hooke's Thermobarometer.
The hydrogen gas in the syphon tube is affected by both the temperature and air pressure. In order to take a reading the temperature is taken from the thermometer and the sliding vernier adjusted until the pointer on the top of the vernier corresponds with the temperature on the register scale. The barometric air pressure is then read from the top of the fluid in the syphon tube. The Sympiesometer was thought to be a safer, reliable and more portable barometer for use primarily at sea.
B7465
SOLD £300