This barometer was used at Sydney Observatory in the late 1800s. The observatory used barometers at its Sydney location and at weather stations throughout country New South Wales to measure atmospheric pressure and, hence, track storm systems . Data from the barometer measurements were collated and analysed by the observatory's astronomers. These observations allowed the astronomers to predict storm systems and movement in Sydney and to the west of the Blue Mountains.
Australia's weather was a mystery to its early colonists, and instruments such as this barometer were used to measure atmospheric pressure and make weather forecasts for Sydney and its surrounds. The first published scientific study of Australian weather was written by William Stanley Jevons, in 1859. Jevons used a barometer, like this one, to observe the rise and fall in atmospheric pressure and translate this into weather forecast rules.
Barometers were also used in the early explorations of inland Australia. Explorers carried their meter long glass barometers filled with mercury, to measure atmospheric pressure at different locations. They were delicate instruments and even when encased in a metal outer tube, they were vulnerable on long inland journeys. These delicate mercury barometers were soon replaced with aneroid barometers, which were a more robust instrument for travelling.
The ability to forecast the weather was an important feature of the observatory's work. This barometer remains of national significance due to its pioneering role in Australian science and its association with Australia's earliest astronomers. It is also significant for its association with nineteenth century meteorological instruments and instrument makers.