Mercury barometers should be transported at an angle of about 45 degrees. In this position the mercury will have risen to fill the tube completely. The lower outlet in those that have one should be closed with the special plug designed for the purpose.
Because Aneroid Barometers do not contain liquid they may be carried in any manner providing they are not subjected to knocks or severe vibration. In addition they can be smaller and combined with other instruments. Some are the size of pocket watches.