Volume Thirteen - Pre-Victorian to the Present Day - Remarkable Connections - Darwin, FitzRoy, Hawkshaw & Wedgwood . . . .

Admiral FitzRoy [1805-1865] and an example of a later FitzRoy type storm-barometer from the period 1876-1884.

FitzRoy's Marine Barometer - A Mariner's Guide to the Weather

In the 1860s, Robert FitzRoy promoted the use of barometers at sea to help sailors recognise approaching changes in the weather.

How did it work? - A barometer measures atmospheric pressure. When pressure is high, the mercury rises. When pressure falls, the mercury drops. A falling barometer could indicate that unsettled weather, strong winds or a gale was approaching. For a sailing master, this information could be extremely valuable and could influence decisions about leaving harbour, seeking shelter, or waiting for safer conditions.

Reading the barometer - Traditional FitzRoy barometers used descriptions such as:

These descriptions were guides rather than guarantees. The movement and rate of change of the barometer were important, and experienced mariners considered the reading alongside wind direction, clouds, sea conditions and their own observations.