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Only with the advent of a special technical device-a diving bell-did man get a real opportunity to invade the realm of Neptune deeper and for a longer time.
The diving bell was known in ancient times. More from Aristotle read:
"In order for sponge collectors to breathe, vessels without lids are lowered into the water, directing their open part downwards, so that they are filled not with water, but with air.
Vessels should be immersed evenly and precisely vertically: even with the smallest tilt, they are filled with water and turned over."
There are medieval engravings of a glass barrel being lowered into the water on a rope.
Inside, it is lit by lamps. According to legend, in this "diving barrel" Alexander the great once plunged into the sea and saw there such wonders as even the most fervent imagination could not imagine. There may be a grain of truth in this legend.
'Alexander the great is sinking into the sea'. Miniature of the beginning of the XIV century.
It is said that during the siege of the mighty tyre, the divers caused the Macedonian king a great deal of trouble. Under the eyes of the invincible commander, they cut the anchor ropes of the ships of his fleet under the water.
Strong current and wind carried the Greek ships into the open sea.
The first reliable description of the diving bell belongs to the pen of the traveler John Teniers:
"You had to see this miracle with your own eyes to believe in the possibility of taking a dip in the water without soaking your clothes and even taking a lighted candle with you."
In 1538, Teniers witnessed an amazing experiment attended by the Emperor Charles V.
Thousands of residents of the old Spanish capital of Toledo watched in mute amazement from the banks of the Tagus as the bell, tied to a thick rope, slowly disappeared under the water. It was built by two Greeks. Both designers sat inside the bell and disappeared into the river with it. Some time later, they appeared on the surface unharmed and dry.
The big drawback of diving bells was the lack of air flow. This forced the divers to return to the top after a short time, so as not to suffocate. The exit was indicated by a person who was engaged in the study of outer space. English astronomer Edmund Halley built a large diving bell in 1716, in which he sat on a bench and stayed under water for more than an hour and a half. He received fresh air from the barrel through a leather hose soaked in beeswax and oil. Water was poured into the barrel through the hole and pushed the air into the bell.
Only a few years later, pumps and bellows were already used to provide fresh air for diving bells. This device, designed by the English engineer John Smeaton, was first successfully used in 1778 on the construction of the port of Ramsgate. Now it was not far off to create a bell with a high-pressure air supply that allows you to descend to great depths.
With the birth of such a diving bell, a technical prototype of modern caissons was born, which were used, for example, in the construction of the Rostock port.
A medieval engraving depicting a dive in a diving bell.
With his invention, Halley also laid the Foundation for the development of ventilated diving equipment, in which the diver can move freely under water.
Already, he designed a bell from which a diver, dressed in waterproof leather clothing, can get out and go a few meters away. The hose will connect it to the bell, which receives fresh air. For the first time to implement this idea in practice managed by the German engineer Kleinert.
Created around 1800, the diving suit consisted of a metal helmet, which was attached to a jacket that reached to the hips, and to semi-short leather sleeves. Through one flexible tube, the bellows pumped fresh air, and through the second, the exhaust air was sucked out.
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