Name/Title
Hydrometric BalanceEntry/Object ID
2013.3.44Description
Charles Chevalier was the maker.
"This is an instrument for indicating the relative density of the air, and the consequent chances of rain or dry weather. It consistes of a balance, from one arm of which is suspended a brass weight, and from the other a large hollow sphere.... If the air becomes heavier, the large sphere, displacing more air, will become buoyant and ascend." (Edw. H. Knight, American Mechanical Dictionary, New York, 1876-77.) It also was used to demonstrate that air has weight by placing the balance under a bell-jar of a vacuum pump. When the air was partially exhausted from the bell jar, the sphere containing air dropped.Collection
Moosnick Museum - Scientific Apparatus