The alarm clock of plato (4hth-5th bc)

It was a hydraulic alarm clock, which was invented by Plato. The upper ceramic vessel supplied the next vessel with water through a tap. When the second vessel was full at the programmed moment, it emptied quickly through an axial siphon to the next airtight vessel and forced the contained air to come out with pressure, whistling through a suringe at its top. Because the flute led to water, the vibrating sound length, produced a chirp with noted of different frequency. After its operation, the third vessel emptied slowly to the lower storage vessel in order to be reused.