Antiquity left its incredible mark on history. Numerous structures amaze with their grandeur and splendor. To date, some of them have been destroyed, only the facades have remained of some, and only a few are still unshakable. In addition, it is difficult to imagine what the buildings of antiquity looked like, it is even more difficult to imagine automatic doors that have not survived to this day.
In the ancient temples of Egyptian Alexandria, automatic doors were installed thousands of years ago. The doors themselves did not survive, because numerous wars between Muslims and Christians ravaged ancient pagan temples. The metal parts of these doors were no exception, but how did the doors work? Let's find out.
The works of the Greek mathematician and mechanic Heron of Alexandria describe in some detail the entire mechanism and principle of its action, which set in motion huge mechanical structures. For this, fairly simple technologies and principles of mechanics were used.
When the priest lit a fire on the altar in front of him, the doors began to slowly open. A metal ball was hidden under the altar, in which fire heated the air. The ball, in turn, expanded and pushed the water through the siphon into a huge container. The container itself was suspended from the chains of a system of scales and pulleys, which turned the doors on their axes when the container became heavier. After the fire on the altar was extinguished, as a result of the rapid cooling of the air in the ball, the water was sucked back. The emptied container rose upward, bringing the pulley system back into motion and the doors were closed.
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Heron also describes that when the doors were opened, a sound similar to a bell was emitted, which played the role of a bell, as well as an alarm signal when breaking. Perhaps this system will seem to a modern person well, very simple and primitive, it was rather complicated to manufacture, especially for people who lived 2000 years ago.
Personally, I believe that such a description cannot be a scientist's fantasy. For such a description, you need to know the principle of operation, as well as at least see it yourself. What do you think? If you agree with me, then like it, let's see how many of us are there! If you do not agree, then I will be glad to see your opinion in the comments.