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A water fountain that seems to defy gravity

  1. Sep 17, 2013 #1
    I saw a strange thing on antiques roadshow that I can't figure out. It was a small water fountain made of glass and metal that appears to make water go uphill. It is totally manual but I don't understand how it gets the water to squirt at a higher level than the water supply.

    On top was a round glass dish with the fountain in the middle which wasn't much more than like a squirt gun shooting up a couple inches and falling back. Below was a blown glass arrangement that looked exactly like an hour glass that is manually flipped over. According to them the water flows out of the top bulb to the fountain above it and drains back to the bottom bulb. When it's all out of the top glass bulb and in the bottom bulb it's flipped over like an hourglass and it cycles again. The glass bulbs, which actually looked like an hour glass had a pinched waist with the water feeds. They looked like they would hold 1 or 2 quarts at most each. The whole thing only stood about 2 feet high. The water came out about 6 inches above the upper bulb. It was working.

    What am I missing here. How does it get the water to flow uphill? Has anyone got any idea how this can work without any power other than just flipping over the water reservoir? It seems to defy gravity.

    edit: I think I figured it out right after I posted this.
     
    Last edited: Sep 17, 2013
  2. jcsd
  3. Sep 17, 2013 #2
    Is it pressurizing air in the lower bulb as it fills? When it's flipped over it's raised high enough to flow out the fountain again?
     
  4. Sep 17, 2013 #3
    Picture ?
     
  5. Sep 17, 2013 #4

    D H

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    Heron's fountain.
     
  6. Sep 17, 2013 #5
    Yep, that's it.
     
  7. Sep 17, 2013 #6

    Andrew Mason

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    The question to ask is: how long does it last if you don't keep flipping the hourglass?

    Essentially there is a large reservoir at the top and an airtight hourglass water reservoir below. Water is fed into the lower reservoir compressing the air inside until it is at the same pressure as the top reservoir. The flipping of the reservoir adds gravitational potential energy to the reservoir. The water from the now upper part of the hourglass increases the air pressure so it is greater than the pressure from the top reservoir. This is then fed back to the top reservoir causing the water in that higher reservoir to rise higher than the water level in the top reservoir. It is a clever way of using a change in potential energy to do work but energy is still conserved. It keeps going because you have to keep flipping the hourglass thereby adding energy to the system.

    AM
     
    Last edited: Sep 17, 2013
  8. Sep 18, 2013 #7

    CWatters

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    Interesting. There is a certain similarity to a counterweight trebuchet. A heavy weight dropped on one end can raise a smaller weight (the projectile) to a greater height than itself. If you only look at the small weight it appears to have gone uphill as well.
     
  9. Mar 28, 2015 #8
    can the heron's fountain principle flow the water up until 1 meter height? i have to do a sort of project that have to use the heron's fountain principle to shoot up the water up till 1 meter height. i cannot find a way on how to do so. i have experimented a basic heron's fountain and also the capillary action but the results were not applicable. i have no basics or knowledge in this principle. i would like to ask for your opinion about it. thank you.
     
  10. Mar 28, 2015 #9

    Drakkith

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    Sure. You just need to have the water from the top basin fall from a high enough height and/or have a narrow enough tube to shoot the water up.
     
  11. Mar 28, 2015 #10
    I use a tube which had 0.5 cm of diameter. I also have to divide the water to 3 division of tube. So, i have to put the top basin above the 1 meter height? is it right? thank you for your opinion.
     
  12. Mar 28, 2015 #11

    Drakkith

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    No, I don't think you need to put the basin above the 1 meter height. You just need to make sure it's falling from a high enough height, at a large enough flow rate, and your output tube is narrow enough. I haven't built one of these before so I can't really give you anything but very general guidelines. You'd need to look into the details of how it functions.

    From wiki: http://en.wikipedia.org/wiki/Heron's_fountain

    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.
     
  13. Mar 28, 2015 #12
    thank you for your opinion. it was very helpful to me. thank you.
     
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