![Heronsbrunnen](https://upload.wikimedia.org/wikipedia/commons/7/71/Heronsbrunnen.jpg)
Heron's fountain is a hydraulic machine invented by the 1st century AD inventor, mathematician, and physicist
Heron of Alexandria
Hero of Alexandria (; grc-gre, Ἥρων ὁ Ἀλεξανδρεύς, ''Heron ho Alexandreus'', also known as Heron of Alexandria ; 60 AD) was a Greek mathematician and engineer who was active in his native city of Alexandria, Roman Egypt. He ...
(also known as Hero of Alexandria).
Heron studied the
pressure of air and steam, described the
first
First or 1st is the ordinal form of the number one (#1).
First or 1st may also refer to:
*World record, specifically the first instance of a particular achievement
Arts and media Music
* 1$T, American rapper, singer-songwriter, DJ, and rec ...
steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be trans ...
, and built toys that would spurt water, one of them known as Heron's fountain. Various versions of Heron's fountain are used today in
physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
classes as a demonstration of principles of
hydraulics
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counter ...
and
pneumatics
Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air.
Pneumatic systems used in industry are commonly powered by compressed air or compressed inert gases. A centrally located and elec ...
.
Construction
![Heron_fountain_principle](https://upload.wikimedia.org/wikipedia/commons/7/77/Heron_fountain_principle.svg)
In the following description, call the 3 containers:
* (A) Top: basin
* (B) Middle: water supply
* (C) Bottom: air supply
And three pipes:
* P1 (on the left in the picture) from a hole in the bottom of basin (A) to the bottom of air supply container (C)
* P2 (on the right in the picture) from the top of the air supply container (C) to the top of the water supply container (B)
* P3 (in the middle of the picture) from the bottom of the water supply container (B), up through the bottom of the basin (A) to a height above the basin's rim. The fountain will issue upwards through this pipe. The maximum height of P3 pipe depends on the height between B and C (see below).
It is okay if A is closed and airtight, but it is not necessary. B and C, however, need to be airtight, and resistant to atmospheric pressure. Plastic bottles will do, but a glass container will do better; balloons will just not work. This is because the fountain works in the following way:
* The energy for moving the water ultimately comes from the water in A descending into C.
* This means the water in B can rise into A only as much as it falls from A to C.
* Water falling from A down to C through pipe P1 will build up pressure in the bottom container; this pressure is proportional to the height difference between A and C.
* Pressure is transmitted by the air through pipe P2 into the water supply B, and pushes the water up into pipe P3.
* Water moving up pipe P3 replaces water falling from A into C, closing the loop.
These principles explain the construction:
* The air in C must not escape through pipe P1, which is why P1 must go to the bottom, so that the water will seal it.
* The air in B must not escape through pipe P3 either, which is why P3 must go to the bottom so that the water will seal it.
* Water must be prevented from going directly through pipe P2 from B to C, so P2 must connect the top of B with C.
* If P2 were connected to C at the bottom, water would seal it and air pressure would not build up in B. So P2 must be connected at the top of C.
Motion
Heron's fountain is not a
perpetual motion
Perpetual motion is the motion of bodies that continues forever in an unperturbed system. A perpetual motion machine is a hypothetical machine that can do work infinitely without an external energy source. This kind of machine is impossible, a ...
machine.
physics.kenyon.edu
Hero's Fountain If the nozzle of the spout is narrow, it may play for several minutes, but it eventually comes to a stop. The water coming out of the tube may go higher than the level in any container, but the net flow of water is downward. If, however, the volumes of the air supply and fountain supply containers are designed to be much larger than the volume of the basin, with the flow rate of water from the nozzle of the spout being held constant, the fountain could operate for a far greater time interval.
Its action may seem less paradoxical if considered as a siphon
A siphon (from grc, σίφων, síphōn, "pipe, tube", also spelled nonetymologically syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in a ...
, but with the upper arch of the tube removed, and the air pressure between the two lower containers providing the positive pressure to lift the water over the arch. The device is also known as Heron's siphon.
The gravitational potential energy
Gravitational energy or gravitational potential energy is the potential energy a massive object has in relation to another massive object due to gravity. It is the potential energy associated with the gravitational field, which is released (conv ...
of the water which falls a long way from the basin into the lower container is transferred by pneumatic pressure tube (only air
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...
is moved upwards at this stage) to push the water from the upper container a short way above the basin.
The fountain can spout (almost) as high above the upper container as the water falls from the basin into the lower container. For maximum effect, place the upper container as closely beneath the basin as possible and place the lower container a long way beneath both.
As soon as the water level in the upper container has dropped so low that the water bearing tube no longer touches the water surface, the fountain stops. In order to make the fountain play again, the air supply container is emptied of water, and the fountain supply container and the basin are refilled. Lifting the water provides the energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...
required.
Reiterative motion and variants
As previously mentioned, the fountain will stop working when water from B has dropped to C. There are ways, however, to make it work again, such as:
* design piping so that once C is full and B is empty, their position can be switched.
* add valves to empty C and replenish B (in effect transferring water from C to B).
* instead of using valves, transfer water up from C to B through boiling and condensing.
* make a 4 container A-B-C-D fountain, which can be turned upside down so that the full and empty container switch places.
There also exist fountains with two liquids of different colors and density- see th
Halite Fountain
Geological phenomena
It is possible that geysers
A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in ...
operate via this mechanism, with the distinction that the spouting of the water at the surface occurs discontinuously. Furthermore, unlike Heron's fountain, which requires that the air supply container be manually emptied of water, geysers have an analogous "air supply container" that is steadily heated by geothermal energy
Geothermal energy is the thermal energy in the Earth's crust which originates from the formation of the planet and from radioactive decay of materials in currently uncertain but possibly roughly equal proportions. The high temperature and pres ...
. When the water level in the air supply container becomes too high, the geothermal heat flux causes the water to boil off and therefore naturally empty the container of water and replace it with water vapor
(99.9839 °C)
, -
, Boiling point
,
, -
, specific gas constant
, 461.5 J/( kg·K)
, -
, Heat of vaporization
, 2.27 MJ/kg
, -
, Heat capacity
, 1.864 kJ/(kg·K)
Water vapor, water vapour or aqueous vapor is the gaseous pha ...
instead of air.
In popular culture
An example of Heron's fountain, built by Larry Fleinhardt
Larry Fleinhardt, Ph.D., is a fictional character in the CBS crime drama ''Numb3rs'', played by Peter MacNicol. He is the best friend and colleague of Charlie Eppes.
Dr. Lawrence Fleinhardt holds the Walter T. Merrick Chair of Theoretical Physic ...
, was featured in the 8th episode (titled "Tabu") of the 4th season of the television show ''Numb3rs
''Numbers'' (stylized as ''NUMB3RS'') is an American crime drama television series that was broadcast on CBS from January 23, 2005, to March 12, 2010, for six seasons and 118 episodes. The series was created by Nicolas Falacci and Cheryl Heuton ...
''.
Heron's Fountain was featured in the first episode of "How Britain Worked
Guy Martin (born 4 November 1981) is a British former motorcycle racer and heavy vehicle mechanic who became a television presenter. In July 2017, Martin retired from motorcycle racing.
Martin started racing in 1998 and in 2004 competed on a ...
" hosted by Guy Martin
Guy Martin (born 4 November 1981) is a British former motorcycle racer and heavy vehicle mechanic who became a television presenter. In July 2017, Martin retired from motorcycle racing.
Martin started racing in 1998 and in 2004 competed on a ...
.
See also
* Hydraulic ram
A hydraulic ram, or hydram, is a cyclic water pump powered by hydropower. It takes in water at one "hydraulic head" (pressure) and flow rate, and outputs water at a higher hydraulic head and lower flow rate. The device uses the water hammer ef ...
* Pulser pump
A pulser pump is a gas lift device that uses gravity to pump water to a higher elevation. It has no moving parts.
Operation
A pulser pump makes use of water that flows through pipes and an air chamber from an upper reservoir to a lower reservoir. ...
* Water hammer
Hydraulic shock (colloquial: water hammer; fluid hammer) is a pressure surge or wave caused when a fluid in motion, usually a liquid but sometimes also a gas is forced to stop or change direction suddenly; a momentum change. This phenomenon com ...
* Venturi effect
The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after its discoverer, the 18th century Italian physicist, Giovanni Battista V ...
Notes
References
* Brown, Henry T.; "507 Mechanical Movements, Mechanisms and Devices", p. 111; 19th edition 1901.
* Hiscox, Gardner D.; "1800 Mechanical Movements, Devices and Appliances", p. 162; 16th edition published 1926 under the name "Mechanical Movements, Power and Devices".
External links
* R. Ya. Kezerashvili, A. Sapozhnikov
"Magic Fountain"
at arxiv.org
* Ayaz, a video of a fountain working, and one way to make on
{{DEFAULTSORT:Heron's Fountain
Hydraulics
Physics experiments
Hellenistic engineering
Ancient inventions