Signedunsigned
Inscribedon glass stem opposite scale: Araeometer nach Baume & Specifischen Gewicht, Temp: 14° Reaum.
FunctionThis hydrometer measures a liquid's density in units of specific gravity (density relative to water) as well as Baumé units. One would let it float in the liquid to be measured and the point on the scale reached by the liquid's surface would be its density.
It was designed to work at a temperature of 14 degrees Réaumur and at other temperatures a conversion table would be needed to correct for the decreasing density of hotter liquids. For all this it would require a thermometer alongside.