Take a glass jar with big volume, some dense stoppers and a tube. Pour a few waters into glass jar. You must drill the aperture on the center stopper for tube. Touch the tube and collect device as is shown in drawing.

You can pump a little air inside it. If the pump isn't present, it is possible to take simply the tube end in a mouth and to blow in it, force how many will suffice.

Release the top end of a tube, you can see the fountain (for a short while). It is air compressed in a bottle, aspiring to extend, forces out water.

You can pump an air through second tube.

The first jar is established above the second jar.

It is work as trigger! The system is counterbalanced until you won't blow in a tube of the first jar. You can start the device having blown in a tube, but then water will begin to flow.

It is'nt the fountain!

It is the compressor.

You can add the third glass jar. It is the fountain.