Ctesibius' Water Clock

Origin
Ctesibius was a Greek inventor who lived in Ptolemaic Egypt when he conducted research into compressed air. He used his discoveries to create pumps, pipe organs and clocks that ran on compressed air blown through water. None of his writings have survived, although he is considered the father of modern pneumatics.

Effects
Releases blasts of compressed air every hour that passes. They normally emanate from the clock itself but can appear several up to several meters away. This blast can appear in the air, moving small objects or propelling them forwards. When it materializes in water, the bubbles created from it contain highly pressurized air; popping them will create a potent blowback in all directions.