Some modern technologies, objects and knowledge were discovered and invented in ancient times. Science fiction writers in their works even use a special term to describe such phenomena: “chronoclasms” - mysterious penetrations of modern knowledge into the past. However, in reality everything is simpler: most of this knowledge was actually discovered by ancient scientists, but then for some reason they were forgotten about and rediscovered centuries later.
In this article you will get to know one of the amazing scientists of antiquity. He brought in his time huge contribution in the development of science, but most of his works and inventions sank into oblivion and were undeservedly forgotten. His name is Heron of Alexandria.
Heron lived in Egypt in the city of Alexandria and therefore became known as Heron of Alexandria. Modern historians suggest that he lived in the 1st century AD. somewhere between 10-75 years. It has been established that Heron taught at the Alexandria Museum, a scientific center of ancient Egypt, which included the famous Library of Alexandria. Most of Heron's works are presented in the form of comments and notes to training courses in various academic disciplines. Unfortunately, the originals of these works have not survived; perhaps they perished in the flames of the fire that engulfed Library of Alexandria in 273 AD, and may have been destroyed in 391 AD. Christians, in a fit of religious fanaticism, destroyed everything that reminded of pagan culture. Only rewritten copies of Heron's works made by his students and followers have survived to our times. Some of them are in Greek, and some are in Arabic. There are also translations into Latin made in the 16th century.
The most famous is Heron's "Metrics" - a scientific work that gives the definition of a spherical segment, a torus, rules and formulas for accurate and approximate calculation of the areas of regular polygons, the volumes of truncated cones and pyramids. The Metrics provides Heron's famous formula for determining the area of a triangle on three sides, and gives rules for the numerical solution of quadratic equations and the approximate extraction of square and cube roots. Metrics examines the simplest lifting devices - lever, block, wedge, inclined plane and screw, as well as some combinations of them. In this work, Heron introduces the term “simple machines” and uses the concept of moment of force to describe their work.
Many mathematicians accuse Heron of the fact that the Metrics does not contain mathematical proofs of the conclusions he made. This is true. Heron was not a theorist; he preferred to explain all the formulas and rules he derived with clear practical examples. It is in the area of practice that Heron surpasses many of his predecessors. The best illustration of this is his work “On the Diopter”, found only in 1814. This work outlines methods for carrying out various geodetic works, and surveying is carried out using a device invented by Heron - a diopter.
1) Diopter
The diopter was the prototype of the modern theodolite. Its main part was a ruler with sights attached to its ends. This ruler rotated in a circle, which could occupy both horizontal and vertical positions, which made it possible to mark directions in both the horizontal and vertical planes. To ensure correct installation of the device, a plumb line and level were attached to it. Using this device and introducing rectangular coordinates, Heron could solve various problems on the ground: measure the distance between two points when one or both of them are inaccessible to the observer, draw a straight line perpendicular to an inaccessible straight line, find the level difference between two points, measure area simplest figure, without even entering the measured area.
Even in the time of Heron, the water supply system on the island of Samos, created according to the design of Eupalinus and passing through a tunnel, was considered one of the masterpieces of ancient engineering. Water through this tunnel was supplied to the city from a source located on the other side of Mount Castro. It was known that in order to speed up the work, the tunnel was dug simultaneously on both sides of the mountain, which required high qualifications from the engineer in charge of the construction. The water pipeline operated for many centuries and surprised Heron’s contemporaries; Herodotus also mentioned it in his writings. Precisely from Herodotus modern world learned about the existence of the Eupalina tunnel. I found out, but didn’t believe it, because it was believed that the ancient Greeks did not have necessary technology for the construction of such a complex object. Having studied Heron's work "On the Diopter" found in 1814, scientists received the second documentary confirmation existence of the tunnel. And only in late XIX century, a German archaeological expedition actually discovered the legendary Eupalina tunnel.
Here is how in his work Heron gives an example of using the diopter he invented to build the Eupalina tunnel:
Points B and D are the entrances to the tunnel. Near point B, point E is selected, and from it a segment EF is constructed along the mountain, perpendicular to the segment BE. Next, a system of mutually perpendicular segments is built around the mountain until a line KL is obtained, on which point M is selected and a perpendicular MD is built from it to the entrance to the tunnel D. Using lines DN and NB, a triangle BND is obtained and angle α is measured.
2) Odometer
The odometer was a small cart mounted on two wheels of specially selected diameter. The wheels turned exactly 400 times per millimeter (an ancient measure of length equal to 1598 m). Numerous wheels and axles were driven by gears, and the distance traveled was indicated by pebbles falling into a special tray. In order to find out how much distance was covered, all that was needed was to count the number of pebbles in the tray.
Internal structure of the odometer.
3) Aeolipile
Aeolipile (translated from Greek as “ball of the wind god Aeolus”) was a tightly sealed cauldron with two tubes on the lid. A rotating hollow ball was installed on the tubes, on the surface of which two L-shaped nozzles were installed. Water was poured into the boiler through the hole, the hole was closed with a stopper, and the boiler was placed over the fire. The water boiled, steam was formed, which flowed through the tubes into the ball and into the L-shaped pipes. With sufficient pressure, jets of steam escaping from the nozzles quickly rotated the ball. Built by modern scientists according to Heron's drawings, the aeolipile developed up to 3500 revolutions per minute!
When assembling the aeolipile, scientists encountered the problem of sealing in the hinge joints of the ball and steam supply tubes. With a large gap the ball received greater degree freedom of rotation, but steam easily escaped through the cracks, and its pressure quickly dropped. If the gap was reduced, the loss of steam disappeared, but the ball also became more difficult to rotate due to increased friction. We do not know how Heron solved this problem. Perhaps his aeolipile did not rotate at such a high speed as the modern model.
Unfortunately, the aeolipile did not receive due recognition and was not in demand either in the era of antiquity or later, although it made a huge impression on everyone who saw it. This invention was treated only as a fun toy. In fact, Heron's aeolipile is the prototype of steam turbines, which appeared only two millennia later! Moreover, aeolipile can be considered one of the first jet engines. Before the discovery of the principle jet propulsion There was only one step left: having the experimental setup in front of us, it was necessary to formulate the principle itself. Humanity spent almost 2000 years on this step. It is difficult to imagine what human history would have looked like if the principle of jet propulsion had become widespread 2000 years ago. Perhaps humanity would have long ago studied all solar system and reached the stars.
Interestingly, the reinvention of Heron's aeolipile took place in 1750. Hungarian scientist J.A. Segner built a prototype of a hydraulic turbine. The difference between the so-called Segner wheel and the aeolipile is that the reactive force rotating the device is created not by steam, but by a jet of liquid. Currently, the invention of the Hungarian scientist serves as a classic demonstration of jet propulsion in physics courses, and in fields and parks it is used to water plants.
4) Steam boiler
The design was a large bronze container, with a coaxially installed cylinder, a brazier and pipes for supplying cold and removing hot water. The boiler was very economical and provided rapid heating of water.
5) "Magic" door opening
As you know, in the era of antiquity, religion had a huge influence on people. There were many religions and temples, and everyone went to communicate with the gods where he liked best. Since the well-being of the priests of a particular temple directly depended on the number of parishioners, the priests tried to lure them with anything. It was then that they discovered a law that is still in force today: nothing can attract people to the temple better than a miracle. However, Zeus descended from Olympus no more often than manna from heaven fell from the sky. And parishioners had to be lured to the temple every day. To create divine miracles, the priests had to use the mind and scientific knowledge of Heron. One of the most impressive miracles was the mechanism he developed that opened the doors to the temple when a fire was lit on the altar.
Air heated from the fire entered a vessel with water and squeezed out a certain amount of water into a barrel suspended on a rope. The barrel, filling with water, fell down and, with the help of a rope, rotated the cylinders, which set the swing doors in motion. The doors opened. When the fire went out, the water from the barrel poured back into the vessel, and a counterweight suspended on a rope, rotating the cylinders, closed the doors.
Quite a simple mechanism, but what a psychological effect on parishioners!
6) Holy water vending machine
Another invention that significantly increased the profitability of ancient temples was the holy water vending machine invented by Heron.
The internal mechanism of the device was quite simple, and consisted of a precisely balanced lever operating a valve that opened under the influence of the weight of a coin. The coin fell through a slot onto a small tray and activated a lever and valve. The valve opened and some water flowed out. The coin would then slide off the tray and the lever would return to its original position, closing the valve. According to some sources, a portion of “sacred” water in the time of Heron cost 5 drachmas.
This invention of Heron became the world's first vending machine and, despite the fact that it brought good profits, it was forgotten for centuries. It was only at the end of the 19th century that vending machines were reinvented.
7) Vessels for "transforming" water into wine
Perhaps Heron's next invention was also actively used in temples.
The invention consists of two vessels connected by a tube. One of the vessels was filled with water, and the second with wine. The parishioner added a small amount of water to a vessel with water, the water entered another vessel and displaced an equal amount of wine from it. A man brought water, and “by the will of the gods” it turned into wine! Isn't this a miracle?
And here is another vessel design invented by Heron for converting water into wine and back.
Half of the amphora is filled with wine, and the other half with water. Then the neck of the amphora is closed with a cork. The liquid is extracted using a tap located at the bottom of the amphora. In the upper part of the vessel, under the protruding handles, two holes are drilled: one in the “wine” part, and the second in the “water” part. The cup was brought to the tap, the priest opened it and poured either wine or water into the cup, quietly plugging one of the holes with his finger.
8) Heron pump
The pump consisted of two communicating piston cylinders equipped with valves from which water was alternately displaced. The pump was driven by the muscular power of two people, who took turns pressing the arms of the lever. It is known that pumps of this type were subsequently used by the Romans to extinguish fires and were distinguished by high quality manufacturing and amazingly precise fitting of all parts. Until the discovery of electricity, pumps similar to them were often used both for extinguishing fires and in the navy for pumping water out of holds in the event of an accident.
As we see, Heron developed three very interesting inventions: aeolipile, piston pump and boiler. By combining them it was possible to get a steam engine. Such a task was probably within the power, if not of Heron himself, then of his followers. People already knew how to create sealed containers, and, as can be seen from the example with the piston pump, they achieved significant success in the manufacture of mechanisms that required high precision manufacturing. A steam engine, of course, is not a jet engine, for the creation of which the knowledge of ancient scientists was clearly lacking, but it would also significantly accelerate the development of mankind.
9) Heron's oil lamp
The most common method of lighting in ancient times was using oil lamps, in which a wick soaked in oil burned. The wick was a piece of rag and burned out quite quickly, and so did the oil. One of the main disadvantages of such lamps was the need to ensure that there was always enough wick above the surface of the oil, the level of which was constantly decreasing. If with one lamp it was easy to keep track of it, then with several lamps there was already a need for a servant who would regularly walk around the room and adjust the wicks in the lamps. Heron invented an automatic oil lamp.
The lamp consists of a bowl into which oil was poured and a device for feeding the wick. This device contained a float and a gear connected to it. When the oil level dropped, the float dropped, rotated the gear, and it, in turn, fed a thin rail wrapped with a wick into the combustion zone. This invention was one of the first uses of a rack and pinion gear.
10) wind organ
The organ created by Heron was not original, but was only an improved design of the hydraulic system - musical instrument, invented by Ctesibius. Hydraulos was a set of pipes with valves that created sound. Air was supplied to the pipes using a water tank and a pump, which created the necessary pressure in this tank. The valves of the pipes, as in a modern organ, were controlled using a keyboard. Heron proposed to automate the hydraulic system using a wind wheel, which served as a drive for a pump that forced air into the reservoir.
11) Fountain of Heron
Heron's Fountain consists of three vessels, placed one above the other and communicating with each other. The two lower vessels are closed, and the upper one has the shape of an open bowl into which water is poured. Water is also poured into the middle vessel, which is later closed. Through a tube running from the bottom of the bowl almost to the bottom of the lower vessel, water flows down from the bowl and, compressing the air there, increases its elasticity. The lower vessel is connected to the middle one through a tube through which air pressure is transmitted to the middle vessel. By exerting pressure on the water, the air forces it to rise from the middle vessel through the tube into the upper bowl, where a fountain emerges from the end of this tube, rising above the surface of the water. The fountain water falling into the bowl flows from it through a tube into the lower vessel, where the water level gradually rises, and the water level in the middle vessel decreases. Soon the fountain stops working. To start it again, you just need to swap the lower and middle vessels.
12) Self-propelled cabinet
For the first time in history, Heron developed a self-propelled mechanism.
The mechanism was a wooden cabinet mounted on four wheels. The interior of the cabinet was hidden behind the doors. The secret of movement was simple: a suspended plate was slowly lowered inside the cabinet, setting the entire structure in motion with the help of ropes and shafts. A supply of sand was used as a speed regulator, which was gradually poured from the top of the cabinet to the bottom. The speed of lowering the slab was regulated by the speed of sand pouring, which depended on how wide the doors were opened, separating the upper part of the cabinet from the lower.
13) Barulk
Unique for its time scientific work is Heron's Mechanics. This book has come to us in the translation of an Arab scholar of the 9th century AD. Costa al-Balbaki. Until the 19th century, this book was not published anywhere and was apparently unknown to science either during the Middle Ages or during the Renaissance. This is confirmed by the absence of lists of its text in the original Greek and in Latin translation, and the lack of mention of it among scholastic authors. In Mechanics, in addition to describing the simplest mechanisms: wedge, lever, gate, block, screw, we find a mechanism created by Heron for lifting loads.
In the book this mechanism appears under the name baroulkos. From the figure it can be seen that this device is nothing more than a gearbox, which is used as a winch. Heron's barulcus consists of several gear wheels driven by hand, and Heron takes the ratio of the diameter of the wheel to the diameter of the axle to be 5: 1, having previously assumed that the load to be lifted weighs 1000 talents (25 tons), and the driving force is equal to 5 talents ( 125 kg).
14) Automatic theater
Heron's work "On Automata" was popular during the Renaissance and was translated into Latin, and was also cited by many scientists of that time. In particular, in 1501 Giorgio Valla translated some fragments of this work. Later translations by other authors followed.
There is a known image of one of Heron’s automata, which was given in his book in 1589 by Giovanni Battista Aleoti.
Most of the drawings of Heron's mechanical dolls have not survived, but various sources contain descriptions of them. It is known that Heron created a peculiar puppet show, which moved on wheels hidden from the audience and was a small architectural structure- four columns with a common base and architrave. Puppets on his stage, set in motion complex system cords and gears, also hidden from public view, reproduced the ceremony of the festival in honor of Dionysus. As soon as such a theater entered the city square, a fire flared up on its stage above the figure of Dionysus, wine poured from a bowl onto the panther lying at the feet of the deity, and the retinue began to dance to the music. Then the music and dancing stopped, Dionysus turned in the other direction, a flame flared up in the second altar - and the whole action was repeated from the beginning. After such a performance, the dolls stopped and the performance ended. This action invariably aroused interest among all residents, regardless of age. But the street performances of another puppet theater, Heron, were no less successful. This theater (pinaka) was very small in size, it was easily moved from place to place. It was a small column, at the top of which there was a model of a theater stage hidden behind the doors. They opened and closed five times, dividing into acts the drama of the sad return of the victors of Troy. The tiny stage showed with exceptional skill how the warriors built and launched sailing ships, sailed on them across the stormy sea and perished in the abyss under the flash of lightning and thunder. To simulate thunder, Heron created a special device in which balls spilled out of a box and hit a board.
In his automatic theaters, Heron, in fact, used elements of programming: the actions of the machines were performed in strict sequence, the scenery replaced each other at the right moments. It is noteworthy that the main driving force that set the theater's mechanisms in motion was gravity (the energy of falling bodies was used); elements of pneumatics and hydraulics were also used. Springs, which became so widely used in Renaissance machines, were not used. The reason for this is simple: the production of springs requires high-quality steel alloys with elasticity, which were not known to the metallurgists of antiquity.
Throughout his life, Heron created many different inventions that were interesting not only to his contemporaries, but also to us, living two millennia later.
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Heron of Alexandria - quite famous person, which caused a lot of controversy. He invented devices that humanity uses to this day, improving them a little - for example, automatic gates. But, unfortunately, some of his labors were in vain.
The years of life of the famous Greek mathematician and mechanic have become the subject of much debate, but they still date back to the second half of the first century AD. Because the exact date unknown, qualified historians and biographers have made assumptions and built various versions. Everyone agreed that he lived after Archimedes, since in his works Heron relies on the knowledge presented in his writings. In addition, in his works, the Alexandrian figure mentions the lunar eclipse of March 13, 62 in such a way that one can conclude that he personally observed the above-mentioned phenomenon.
The details of the life of this scientist are unknown; exact data relating to his biography has not been preserved. Perhaps historians of that time were not too interested in this person, but one way or another, all dates are approximate. The birthplace of the great inventor was the city of Alexandria.
Heron is considered a great and talented engineer in human history. He is credited with the invention of automatic doors, the self-loading crossbow, the steam turbine, and the automatic puppet theater. From this we can conclude that he devoted especially much time to automation.
Heron loved the exact sciences with all his soul; his thoughts were completely occupied by geometry, mechanics, and optics. The teacher of this famous inventor is considered to be an equally famous scientist ancient Greece- Ctesibia, because it was his name that Heron repeatedly mentioned in his notes. Although he also used the inventions of his predecessors - Euclid and Archimedes.
The most important property of Heron of Alexandria are the books that remained after him. These works describe not only the innovations of the author himself, but also the knowledge and discoveries of his contemporaries and other ancient Greek discoverers. The most famous works Heron - works entitled “Metrics”, “Pneumatics”, “Automatopoetics”, “Mechanics”. Descendants saw the last notes only in Arabic; moreover, not all of the author’s above-mentioned works were preserved in the original, author’s version. For example, the manuscript in which Heron describes mirrors exists only in Latin.
In his works on geodesy, the author talks about the first odometer. This is the name of a device that measures distance. In 1814, Heron’s work “On the Diopter” was published, where he sets out the parameters of land surveying, which are based on the use rectangular coordinates. A diopter is an elementary device for measuring angles, and its discovery is attributed to Heron. The bright mind of this famous scientist was visited by truly brilliant thoughts, but most of his innovations in the Middle Ages were rejected by his contemporaries. This was explained by the fact that such phenomena were of no practical interest.
In his work entitled “Mechanics”, which consists of 3 parts, Heron described 5 types of elementary mechanisms - gate, lever, wedge, block and screw. The above devices formed the basis for more complex structures, and they are associated with “ Golden Rule mechanics” - an increase in strength when using these mechanisms is achieved by increasing the time spent.
The ball of Aeolus, the progenitor of modern steam turbines, is also mentioned in his works. It can also be considered the first heat engine. The above-mentioned device was essentially a bronze cauldron, which was supported on supports. A pair of tubes were attached to its lid, and they held the sphere. Steam flowed through tubes from the boiler into the sphere, and as it exited the tubes it rotated the sphere.
The fire water pump, which was also discussed in the manuscripts of the discoverer from Alexandria, continuously pumped water, and the miracle fountain (also called Heron’s fountain) operated without using energy.
Many of the scientist’s works concerned optics. He conducted experiments and analyzed problems involving the refraction of light rays, and made assumptions. For example, in the treatise “Catoptrica”, famous explorer explained the straightness of light rays by the incredibly high speed of their propagation, as well as the type and shape of the mirror that participated in the experiment.
Mathematics treatises contained a large number of formulas. The scientist also had descriptions geometric shapes. Everyone knows Heron's formula from school - it is used to determine the area of a triangle along the semi-perimeter and three sides. And, although it was Archimedes who deduced it, this theorem bears the name of a scientist from Alexandria.
The talented inventor created another incredibly useful device - an automatic oil lamp. In antiquity, an oil lamp was used for lighting, namely a bowl that contained a burning wick, previously soaked in oil. A small piece of fabric acted as a wick, which burned very quickly. The main disadvantage of such a lighting device was that it was necessary to constantly adjust the oil level in the bowl. And if one such lamp could still be controlled, then a servant had to be assigned to several similar devices, who constantly added oil to the lamp and replaced the burnt piece of fabric with a new one. Heron improved this design by attaching a float and a gear to the bowl. When the oil in the bowl ran out, the float dropped to the bottom, and the gear wheel turned and fed a new wick.
Heron paid a lot of attention to theorems and formulas, but in his works he only gave examples of these formulas, and did not describe their proof or application. Therefore, not all of them were in demand in ancient Greece. In the same way, the mechanisms created by Heron did not immediately find application, because in the ancient world all the hard work was done by slaves. And the work of mechanics of that time was not appreciated; it was equated to the work of slaves.
That is why most of Heron’s inventions were set aside for several centuries. Some of the scientist’s inventions were subsequently rediscovered, but by other scientists who did not take credit for other people’s discoveries, but simply did not hear anything about the inventor from Alexandria and his achievements.
The name of Heron is still on everyone’s lips to this day, and this is connected not only with his theorem.
There is another reason. In 1976, the International Astronomical Union named a crater on the back side Moon, immortalizing it for all time. So, Heron of Alexandria made many discoveries, but only a small part of them was appreciated.
Archimedes' doctrine of the equilibrium of liquids was used in the brilliant inventions of Heron of Alexandria, to which we now turn.
Heron of Alexandria, a student of Ctesibius, the son of a barber and also a skilled inventor, lived in the second half of the 2nd century. BC e. (about 120 g). In the person of Heron we are dealing with a practitioner of ancient science. In the field of mathematics, Heron searched for relationships that would best suit the purposes of land surveying, and developed calculation methods, in particular methods of approximate calculations. He gave a rule to determine the area of a triangle based on its sides; in its modern form, this rule is written in the form of the so-called Heron’s formula:
Heron's inventions were not of the nature of technical applications; they can rather be called technical toys, and their history is an instructive example of how ingenious inventions that do not meet the needs of the era remain fruitless.
Heron's teacher - Ctesibius, as already mentioned, he was a major inventor. He invented a water clock with a pointer (Fig. 28), a water organ, and a fire engine. The latest invention had almost modern look. Heron describes this machine as follows:
“Fire pumps used to extinguish fires are made as follows (Fig. 29): two metal cylinders are drilled from the inside with a lathe according to the size of the piston, just as a well craftsman drills out “pumps.” KL and MN are precisely fitted pistons. Cylinders connected to each other by a pipe XODE and provided externally (inside the pipe XODE,) - valves P and R that open outward. In the bottom of the cylinders there are holes S and T, which are closed by smooth hinge plates (valve flaps); bolts are passed through them, which are firmly soldered or firmly connected to the bottom of the cylinder using rivets placed on their outer ends. The pistons are equipped with rods S fixed in the middle; a rod (balancer Za) is connected to them, which in the middle rotates around the bolt; the piston rods S rotate around bolts b and v. Above the hole in the XODEy tube, another vertical fork-shaped tube S is installed, equipped with a faucet-like nozzle, through which water is thrown out in the same way as we already said above when describing the vessel that threw out water using air compressed in it.”
The valve mentioned in this description (Fig. 30) was apparently also invented by Ctesibius. Heron describes this device as follows: “Two quadrangular plates of appropriate thickness are made, finger-length on each side. With their surfaces they are fitted to each other and ground so that neither air nor water can pass between them. Let these plates be ABCD and EFGH. In one of them, namely ABCD, a round hole is drilled, one-third the width of a finger. The edge of the CD is connected by a hinge to the edge of the FE, so that the ground sides of the metal plates lie on top of each other. When one wants to use these valves, the plate ABCD. soldered tightly to the hole through which air or water must enter. In this case, when the pressure from the inside, the EFGH plate opens and allows air or water to pass through. But then the pressure of the air or water will press the EFGH plate against the hole through which the air or water enters."
As we can see, technology, in particular metal processing technology, reached a fairly high level at this time. Below we will see that Heron even implemented a heat engine. But this technology, as has been repeatedly pointed out, could not bring about an industrial revolution, could not play the revolutionary role that it played during the period of primitive accumulation, during the period of bourgeois revolutions.
Heron's famous inventions are described in the treatise "Pneumatics" that has come down to us. In his theoretical positions, Heron is aligned with Aristotle, but with significant amendments. He, like Aristotle, believes that there is no emptiness in nature, but “although there is no large empty space in nature, nevertheless very small empty spaces exist in liquids, fire and other bodies.”
Heron considers elasticity, mixing of various liquids, expansion of bodies due to heating, etc. as proof of the existence of empty spaces between particles. Heron considers air to be a body consisting of very light and mobile particles. Heron believes that proof that air is a body is, for example, the fact that a vessel turned upside down when immersed in another vessel with water does not fill with water. If a hole is made in the bottom of the vessel through which air can escape, then water will fill the inside of the immersed vessel, displacing the air through this hole. Nature does not allow abnormally large gaps between the particles of the body and, in this sense, is “afraid of emptiness.” So, for example, if a certain amount of air is sucked out of a vessel, due to which the distance between the particles of the remaining air increases, then the vessel will have suction properties (blood-sucking cups): the skin of the finger covering the hole of the vessel will be drawn inward. If the finger is removed, outside air enters the vessel, filling its volume until the distances between the particles reach a normal value. In this we should look for the reasons for the strength of bodies. A liquid stream, according to Heron, also has tensile strength *. Once a column of liquid has arisen, it cannot rupture, because this would lead to the formation of a significant void. This is the basis of Heron's explanation of the action of the siphon.
* (Galileo, in his doctrine of the strength of materials, restored the views of Heron.)
Let's immerse the elbow tube AHDBCKL (Fig. 31) in a vessel filled with water to level FG. The water in the knee will reach the I level, which coincides with the FG level. If you suck air from L with your mouth, then, due to the indicated property of not allowing significant voids, the air will suck water from the vessel along the knee AHD. If the vacuum is sufficient, water will fill the upper part of tube B and begin to flow down the elbow CKL. Trying to fall like a weight in both knees, it cannot fall, because this would lead to a rupture of the jet. If the fluid level in the left knee is lower than in the right, then the left load of water will pull over the right one and the water will flow from a higher level to a lower one until the fluid levels on the left and right are equal, or until it is emptied vessel (if its bottom level is high enough).
So, in Heron’s theory we are dealing with two main assumptions: a) the impossibility of breaking the jet, b) the overhang of the jet by a longer part, which leads to the flow of liquid from a higher level to a lower one. Once the resulting liquid stream behaves like a rope thrown over a block. The rope will "run" towards the longer part. Outside air pressure does not play a role in this explanation.
It is curious that this explanation of Heron was relatively recently restored as the newly discovered “principle of action of the liquid siphon.” In Professor Pohl's book "Introduction to Mechanics and Acoustics" we come across the statement emphasized by the author that "the siphon principle has nothing to do with air pressure", in explanation of which (i.e. the statement) an image of a chain running off a block is given. Leaving aside the reticence of Prof. Fields about the fact that the principle he put forward against the usual “elementary” interpretation of the action of the siphon dates back two thousand years, we note that prof. Paul also passes over in silence some of the difficulties associated with Heron's explanation, difficulties that were already known to Heron himself. Namely, if you imagine that the left end of the chain is shorter, but consists of several chains, then you can not only achieve balance, but also the chain running towards the short part. In other words, if you make a siphon tube from elbows of unequal thickness, making the short elbow thicker, you can achieve a transfusion of liquid from a lower level to a higher one. Heron points out that this is impossible. Fill the U-shaped tube with liquid to the very top. Let's close the ends of the tube and tip it into two vessels with unequal levels of liquids so that the thick elbow of the tube is immersed in the vessel with the highest level of liquid. By removing the fingers from the ends of the tube, we will establish communication between the masses of liquid in both vessels (the column of liquid in the siphon tube cannot break). But, according to Archimedes, the communicating masses of liquid will be in equilibrium if and only if the free surface is a spherical surface with its center at the center of the Earth. Consequently, the liquid will flow with top level to a lower one until the levels are equal. We see that Heron, starting from Archimedes, essentially formulates the principle of communicating vessels. As for the principle of the siphon, Heron's explanation, restored by Paul, reflects one aspect of the siphon's operation, but not all. Pascal's research represents a major step forward in understanding the action of the siphon, and not a step back, as Prof. wants to say. Paul. Heron's peculiar understanding of the "fear of emptiness" gives him the opportunity to explain the action of the pipette, which he has in the form of " magic ball"If, leaving the top hole open, you immerse the ball in liquid, then the liquid will enter through the holes in the bottom of the ball into it. If you now close the hole with your finger and remove the ball, then water will not pour out through the lattice bottom of the ball, because this would lead to the formation of voids in the internal air space, you can pour out the liquid anywhere by removing your finger.
Heron invented siphons of various shapes. We will mention here the double siphon and the siphon with a constant flow rate (siphon with a float). A double siphon (Fig. 32) is a tube that is closed at the top but open at the bottom. A second tube is placed inside this tube, open at both ends; the upper end does not reach the bottom of the outer tube. If the vessel has a hole in the bottom of such a size that the inner tube of the siphon fits into it, tightly fitting to the edges, then liquid can be poured into the vessel until its level is such that the outer tube of the siphon is filled to the very bottom . Then, according to the siphon principle, the liquid will flow through the inner tube until the vessel is empty. The double siphon explains the action of Heron's "magic cup". In a siphon with a constant flow rate (Fig. 33). the inner elbow is fixed in a bowl floating on the surface of the liquid in the vessel. As the liquid level decreases, the siphon also lowers, so that the outlet remains below the liquid level always by the same amount. As an example to illustrate Heron’s ingenuity, let us describe his “singing bird” machine gun (Fig. 34). The bird whistles when the owl is not looking at it, and falls silent when the owl turns to it. The operation of this device is based on the appropriate selection of double siphons. When liquid flows through the funnel into the upper vessel, it displaces air, which, passing through the tube, causes a whistle. As the liquid level in the reservoir rises, it begins to flow through the siphon into the lower bucket. This will eventually overload the bucket, which will pull on the counterweight and cause the owl to turn. The siphon is selected so that at this moment the flow out of the reservoir exceeds the rate of liquid inflow - the bird does not sing. Then the lower siphon comes into effect. As the tank empties, the bucket will also empty - the owl will turn away. The machine starts working again.
It is especially remarkable that Heron was the first to use the driving force of heat. Let us first get acquainted with the effect of his “Aeolipile”. Heron's aeolipile is an iron ball that can rotate around horizontal axis(Fig. 35). At the top of the ball there is an outlet tube bent at a right angle; the same tube, but bent in the opposite direction, is located at the bottom of the ball. The steam coming from the tank through the side pipes is expelled by the outlet pipes. The reaction of the steam jet (turbine principle) causes the ball to rotate.
Thus, almost two thousand years before the invention of the steam engine, a heat engine was first constructed. But this was a premature invention, and a new search for a heat engine began in the 17th century.
Let us give as an example of the use of the driving force of heat - an altar with automatically opening doors when the sacrificial fire is lit (Fig. 36).
“In the temple there is a hollow altar DE, which is connected by means of a tube FG to a spherical vessel PH, half filled with water. A U-shaped tube KLM is soldered into the ball. The rotation axes of both door leaves are extended to the basement floor, where they are inserted into the corresponding sockets. two chains are wound on the axes. At the end of one chain a weight is placed, which with its weight tends to close the door, and on the other, wound in the opposite direction on the door axes, hangs a vessel of another, wound in the opposite direction XN, which, being empty, is lighter than the weight B. this vessel passes through one of the elbows of a U-shaped tube, which is so installed that when the doors are closed, this elbow extends almost to the bottom of the vessel.
When a fire is lit on the altar, the altar heats up, the air enclosed in it expands, presses on the water in the ball, and raises it through a U-shaped tube into a suspended vessel, which thereby lowers and thus opens the door.
We will limit ourselves to the examples considered. From what has been said it is clear how ingenious Heron's inventions were. Only his hydraulic machines, which improved the technology of water-drawing machines, received practical significance. The rest of the inventions served as funny toys, nothing more. Only resurgent new science turned to Heron's inventions, developing them further on a new basis.
(1st century AD), an outstanding mathematician, surveyor, mechanic and engineer of the Hellenistic era. No biographical information has been preserved. It is known that he lived and worked in Alexandria, as most scientists assume, in the 1st century. AD He left behind works on mechanics, mathematics and geodesy (at this time, according to the classification of Gelinos of Rhodes (1st century BC), mathematics included arithmetic, geometry, astronomy, optics, geodesy, mechanics, musical harmony and practical calculations) ; invented a prototype steam engine and precision leveling instruments. From the works of Heron of Alexandria, “Mechanics” is known (in Arabic translation), “About lifting mechanisms”, as well as the above-mentioned “Metrics” and “Dioptra”. Three treatises of Heron are known in Greek: “Pneumatics”, “The Book of War Machines”, “Theater of Automata”, “Catoptika” (the science of mirrors; preserved only in Latin translation), etc.
The most popular were Heron's automata, such as an automated theater, fountains, etc. Heron described a "diopter" - a device for measuring angles - a prototype of a modern theodolite, based on the laws of statics and kinetics, he gave a description of a lever, block, screw, military machines. In optics he formulated the laws of light reflection, in mathematics - methods for measuring the most important geometric figures. Heron used the achievements of his predecessors: Euclid, Archimedes, Strato of Lampsacus. His style is simple and clear, although sometimes it is too laconic or unstructured. Interest in the works of Heron arose in the 3rd century. n. e. Greek, and then Byzantine and Arab students commented on and translated his works.
Heron's mathematical works are an encyclopedia of ancient applied mathematics. His works have not reached us in full. The best of his books, “Metrics,” gives a definition of a spherical segment, rules and formulas for accurate and approximate calculation of the areas of regular polygons, volumes of truncated cones and pyramids, and the so-called Heronian formula for determining the area of a triangle on three sides, found in Archimedes; rules for the numerical solution of quadratic equations and the approximate extraction of square and cube roots are given. Metrics examines the simplest lifting devices - lever, block, wedge, inclined plane and screw, as well as some combinations of them. When researching " Simple machines"(the term was introduced by him) uses the concept of moment. He took into account the force of friction and recommended, when working with complex mechanisms, to slightly increase the forces applied to them. In “Pneumatics” he examined a number of ingenious hydropneumatic devices. In “The Theater of Automata” he described the temple and theater automata of his time. Heron has the ratio C2 » 17/12, where 17/12, as is known, is the fourth suitable fraction for C2. The content of Heron's mathematical works is dogmatic; the rules are most often not derived, but explained with examples. This brings Heron's works closer to the works of mathematicians Ancient Egypt and Babylon. In 1814, Heron’s essay “On the Diopter” was found, which set out the rules for land surveying, which were actually based on the use of rectangular coordinates. Heron described the main achievements ancient world in Applied Mechanics. He invented a number of instruments and machines, in particular a device for measuring the length of roads, which operated on the same principle as modern taximeters, a machine for selling “sacred water,” various water clocks, and more. The influence of Heron's work can be traced throughout Europe until the Renaissance.
I hope many will be curious, he is truly an amazing person... unfortunately I don’t remember where I downloaded this article.
Rice. 1. Heron Heron of Alexandria lived in Egypt in the city of Alexandria and therefore became known as Heron of Alexandria. Modern historians suggest that he lived in the 1st century AD. somewhere between 10-75 years. It has been established that Heron taught at the Alexandria Museum, the scientific center of ancient Egypt, which included the famous Library of Alexandria. Most of Heron's works are presented in the form of comments and notes to training courses in various academic disciplines. Unfortunately, the originals of these works have not survived; they may have perished in the fire that engulfed the Library of Alexandria in 273 AD, and they may have been destroyed in 391 AD. Christians, in a fit of religious fanaticism, destroyed everything that reminded of pagan culture. Only rewritten copies of Heron's works have survived to this day... The Metrics examines the simplest lifting devices - a lever, a block, a wedge, an inclined plane and a screw, as well as some of their combinations. In the work “On the Diopter”. This work outlines methods for carrying out various geodetic works, and surveying is carried out using a device invented by Heron - a diopter. 
Rice. 2. Diopter The diopter was the prototype of the modern theodolite. Its main part was a ruler with sights attached to its ends. This ruler rotated in a circle, which could occupy both horizontal and vertical positions, which made it possible to mark directions in both the horizontal and vertical planes. To ensure correct installation of the device, a plumb line and level were attached to it. Heron gives a description of the device he invented for measuring distances - the odometer. 
Rice. 4. Odometer (appearance) 
Rice. 5. Odometer (internal structure) The odometer was a small cart mounted on two wheels of a specially selected diameter. The wheels turned exactly 400 times per millimeter (an ancient measure of length equal to 1598 m). Numerous wheels and axles were driven by gears, and the distance traveled was indicated by pebbles falling into a special tray. In order to find out how much distance was covered, all that was needed was to count the number of pebbles in the tray. The operation of the odometer is clearly demonstrated in this video. One of the most interesting works Gerona is "Pneumatics". The book contains descriptions of about 80 devices and mechanisms operating using the principles of pneumatics and hydraulics. The most famous device is the aeolipile (translated from Greek: “ball of the wind god Aeolus”). 
. Rice. http://www.youtube.com/watch?v=WvZuFx6iPGY&NR=1 6. http://www.youtube.com/watch?v=GLsRygxnwu8&feature=related Eolipil Eolipil was a tightly sealed cauldron with two tubes on the lid. A rotating hollow ball was installed on the tubes, on the surface of which two L-shaped nozzles were installed. Water was poured into the boiler through the hole, the hole was closed with a stopper, and the boiler was placed over the fire. The water boiled, steam was formed, which flowed through the tubes into the ball and into the L-shaped pipes. With sufficient pressure, jets of steam escaping from the nozzles quickly rotated the ball. Built by modern scientists according to Heron's drawings, the aeolipile developed up to 3500 revolutions per minute! When assembling the aeolipile, scientists encountered the problem of sealing in the hinge joints of the ball and steam supply tubes. With a large gap, the ball received a greater degree of freedom of rotation, but steam easily escaped through the gaps, and its pressure quickly dropped. If the gap was reduced, the loss of steam disappeared, but the ball also became more difficult to rotate due to increased friction. We do not know how Heron solved this problem. Perhaps his aeolipile did not rotate at such a high speed as the modern model. Unfortunately, the aeolipile did not receive due recognition and was not in demand either in the era of antiquity or later, although it made a huge impression on everyone who saw it. This invention was treated only as a fun toy. In fact, Heron's aeolipile is the prototype of steam turbines, which appeared only two millennia later! Moreover, aeolipile can be considered one of the first jet engines. There was one step left before the discovery of the principle of jet propulsion: having an experimental setup in front of us, it was necessary to formulate the principle itself. Humanity spent almost 2000 years on this step. It is difficult to imagine what human history would have looked like if the principle of jet propulsion had become widespread 2000 years ago. Perhaps humanity would have long ago explored the entire solar system and reached the stars. I confess that sometimes the thought arises that the development of humanity has been deliberately delayed by someone or something for centuries. However, we will leave this topic for development by science fiction writers... It is interesting that the re-invention of Heron’s aeolipile took place in 1750. Hungarian scientist J.A. Segner built a prototype of a hydraulic turbine. The difference between the so-called Segner wheel and the aeolipile is that the reactive force rotating the device is created not by steam, but by a jet of liquid. Currently, the invention of the Hungarian scientist serves as a classic demonstration of jet propulsion in physics courses, and in fields and parks it is used to water plants. Another outstanding invention of Heron related to the use of steam is the steam boiler. 
. Rice. 7. Heron's steam boiler The design was a large bronze container, with a coaxially installed cylinder, a brazier and pipes for supplying cold and discharging hot water. The boiler was very economical and provided rapid heating of water. A significant part of Heron’s “Pneumatics” is occupied by a description of various siphons and vessels from which water flows by gravity through a tube. The principle inherent in these designs is successfully used by modern drivers when it is necessary to drain gasoline from a car tank. As you know, in the era of antiquity, religion had a huge influence on people. There were many religions and temples, and everyone went to communicate with the gods where he liked best. Since the well-being of the priests of a particular temple directly depended on the number of parishioners, the priests tried to lure them with anything. It was then that they discovered a law that is still in force today: nothing can attract people to the temple better than a miracle. However, Zeus descended from Olympus no more often than manna from heaven fell from the sky. And parishioners had to be lured to the temple every day. To create divine miracles, the priests had to use the mind and scientific knowledge of Heron. One of the most impressive miracles was the mechanism he developed that opened the doors to the temple when a fire was lit on the altar. The principle of operation is clear from the animated drawing. 
Rice. 8. Diagram of the “magical” opening of doors in a temple© P. Hausladen, RS Vöhringen Air heated from the fire entered a vessel with water and squeezed a certain amount of water into a barrel suspended on a rope. The barrel, filling with water, fell down and, with the help of a rope, rotated the cylinders, which set the swing doors in motion. The doors opened. When the fire went out, the water from the barrel poured back into the vessel, and a counterweight suspended on a rope, rotating the cylinders, closed the doors. Quite a simple mechanism, but what a psychological effect on parishioners! Another invention that significantly increased the profitability of ancient temples was the holy water vending machine invented by Heron. 
Rice. 9. Vending machine for selling “holy” water The internal mechanism of the device was quite simple, and consisted of a precisely balanced lever that controlled a valve that opened under the influence of the weight of a coin. The coin fell through a slot onto a small tray and activated a lever and valve. The valve opened and some water flowed out. The coin would then slide off the tray and the lever would return to its original position, closing the valve. According to some sources, a portion of “sacred” water in the time of Heron cost 5 drachmas. This invention of Heron became the world's first vending machine and, despite the fact that it brought good profits, it was forgotten for centuries. It was only at the end of the 19th century that vending machines were reinvented. Perhaps Heron's next invention was also actively used in temples. 
Rice. 10. Vessels for “transforming” water into wine The invention consists of two vessels connected by a tube. One of the vessels was filled with water, and the second with wine. The parishioner added a small amount of water to a vessel with water, the water entered another vessel and displaced an equal amount of wine from it. A man brought water, and “by the will of the gods” it turned into wine! Isn't this a miracle? And here is another vessel design invented by Heron for turning water into wine and back 
. Rice. 11. Amphora for pouring wine and water Half of the amphora is filled with wine, and the other half with water. Then the neck of the amphora is closed with a cork. The liquid is extracted using a tap located at the bottom of the amphora. In the upper part of the vessel, under the protruding handles, two holes are drilled: one in the “wine” part, and the second in the “water” part. The cup was brought to the tap, the priest opened it and poured either wine or water into the cup, quietly plugging one of the holes with his finger.
