In a first view the two first sub-units can be viewed and after scrolling the following two sub-units.

The visualization of Gael fits perfectly into a larger screen.
The visual unit of the browser window is devided up into smaller portions by using 4 tables:
- 1 table of 1 column and 1 row
- 1 table of 1 column and 2 rows
- 2 tables of 2 columns and 2 rows.

The two pictures of Cyril show the two combinations given by the text in a rather abstract way.

For me, this visualization is clear and easy to understand - no animation needed. As long as you are familiar with abstract representations of molecules and density.
This visualization is more analytic and explaining.

Before Gael starts his visualization, he gives a short introduction explaining his visual representations of cold air and warm air.
In the two animated gifs of his visualization he doubles the same information by adding text to the graphic information.

The two pictures of Cyril continue visualizing the text informations in a rather abstract way:
- Warm air with lower density and lower specific weight and lower pressure onto the mercury column.
- Cold air with higher density and higher specific weight and higher pressure onto the mercury column.

Still, you have to be familiar with abstract representations of molecules and density. Cyril's visualization is more analytic and explaining again - demanding from the viewer the physical concepts of density, pressure, and scaling.

I would like to see the mercury container within the cold air getting much more empty than that. The difference to the other mercury container should be clearer.
I like the two columns starting together and falling back at once together - the column within the warm air waiting for the other one to reach its top. The impression of starting again is strong.

Gael combines the two movements in one animated gif.
Again, his naturalistic approach is easy to understand: by showing a cloud of warm air going up and another cloud of cold air falling down his visualization remains more describing and demonstrating.

The two pictures of Cyril continue the same rather abstract visualizing style.

It is nice to see the warm air in contact with the surface getting colder. But before starting all over again, there should be visual sign of the end of the process and of the beginning of the next turn. Something that tells the viewer: we go back to zero and start again.

The same is true for the cold air becoming warm. The way up of the warmer part is good visualized. And this animated gif indicates the restart of the whole program by reintroducing the surface that disappeard during the process.

The corresponding visualizations of Gael are not very clear in the message. He leaves his naturalistic approach and tries out a more symbolic style which is much harder to understand.

The warm air is getting colder and then warmer again, because there is no sign indicating the restart of the cycle.