progresses of war weapons (crossbows, catapults and siege machines) and also navigation became safer, thanks to the construction of firm boats and big lighthouses, such as Alexandria lightouse. There was the invention of hydraulic machines used to embellish royal palaces with fountains. The major developments of hydraulic technics were the construction water mills and the planning of big aqueducts. The limit of Alexandrian technology was that it was used within limits, because slaveâ€™s work was efficient and it had a lower cost.
Technology and Production The Lighthouse of Alexandria: it is consedered one of the seven wonders of the ancient world and it was constructed on the island of Pharos, in front of the port of Alexandria, in the years between 300 B.C. and 280 B.C. and it reamained operable until the XIV century, when it was destroyed by two earthquakes. It was constructed by Substratum of Cnidus, a Greek merchant; the project was started by Ptolemy I Soter, at the beginning of his reign, and was completed by his son Ptolemy II Philadelphus. The aim was that of increasing maritime traffic safety both in entrance and exit, which was made dangerous by the orographic reliefs and by the various sandbanks in the area of the sea overlooking the port of Alexandria.
Technology and Production The pump for the water increase is an important and long-lasting invention by Ctesibius. Described by Vitruvius, who attributed this invention to Ctesibius, and by Hero, who didnâ€™t cite the author. The pump was constituted by two bronze cylinders in which, thanks to a revolving bar, two hermetic pistons were turned up and down one after the other. Both cylinders communicated with a vertical tube. Actioning the pump into the water, it filled the cylinders when the corrispondent pistons turned up, while when they turned down, thanks to the closure of specific valves, that denied it to flow back into the other cylinder, it was forced to go up the tube.
Technology and Production The water clock: the ancient instrument used to get the impression of the passing of the time was the water hourglass, dated back to the pharaonic Egypt. Ctesibius transformed this instrument into the water clock, which was a real measurement instrument, thanks to different expedient, described by Vitruvius. The basic idea was that of making constant the idea of the pressure present into the