Hydrostatic

According to the IAU, a "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

Galileo designed a variety of scientific instruments. Among them was the hydrostatic balance. This was an instrument used to find the specific gravity of objects by weighing them in water.

[...] the electric fan drive and Drayton regulator temperature control employed on the prototypes have been superseded on the production version by Serck-Behr hydrostatic drive from an engine-driven pump with thermostatically controlled fan speed regulation.