The baroscope is a teaching aid for experimental verification of the fact that the principle of Archimedes is valid not only for liquids but also for air and all gases.
It consists of a scale with two arms, the beam of which has hooks instead of pans; a large hollow brass ball is attached to one arm and a small, solid brass ball or another counterweight is attached to the other arm to balance the other.
The baroscope was invented some time around 1650 by Otto von Guericke (1602-1686), the inventor of the pneumatic machine, who called it a static barometer. He used it to observe miscellaneousations in atmospheric pressure by means of the shifts of the needle of a high-precision balance.
In the baroscope conserved in the museum, the beam is made of steel (length 14 cm) and is suspended from a brass column held by a circular base, it too brass.
The overall height of the instrument is 20.5 cm and the hollow ball, which is made of brass, has a diameter of 10 cm.