Baroscope
Pronunciation : Bar"o*scope
Part of Speech : n.
Etymology : [Gr. weight + -scope: cf. F. baroscope.]
Definition : Defn: Any instrument showing the changes in the weight of the atmosphere; also, less appropriately, any instrument that indicates - or foreshadows changes of the weather, as a deep vial of liquid holding in suspension some substance which rises and falls with atmospheric changes.
Source : Webster's Unabridged Dictionary, 1913