Used to determine the altitude of objects in the sky.[21][22] Canal lock early 3rd century BC Built into Ancient Suez Canal under Ptolemy II (283–246 BC).[23][24][25] Ancient Suez Canal early 3rd century BC Opened by Greek engineers under Ptolemy II (283–246 BC), following earlier, probably only partly successful attempts.[26] Lighthouse c. 3rd century BC According to Homeric legend, Palamidis of Nafplio invented the first lighthouse, although they are certainly attested with the Lighthouse of Alexandria (designed and constructed by Sostratus of Cnidus) and the Colossus of Rhodes. However, Themistocles had earlier established a lighthouse at the harbor of Piraeus connected to Athens in the 5th century BC, essentially a small stone column with a fire beacon.[27] Water wheel 3rd century BC First described by Philo of Byzantium (c.