For comparable examples and a full account of the station barometer's functions see Edwin Banfield Barometers, Stick or Cistern or Tube, Baros Books, 1985, pp.181-186. These highly accurate barometers were used at metereological stations for detailed recording work.
When Captain Edward Sabine F.R.S. persuaded the British Government to establish a number of metereological stations across the Empire each needed to be equipped with as accurate a barometer as possible. The design was entrusted to Newman. As well as being extremely accurate, these barometers were very resilient, arriving at their destinations around the globe with their corrections almost unaltered. Once the cistern is closed they are very easy to move. See W.E. Knowles Middleton The History of The Barometer, Baros Books, 1964, pp.218-220.