Heating, Ventilation and Air Conditioning

Take a straw and throw it up into the air,—you may see by that which way the wind is.

So it is with air: there is the brightest variety which we call aether, the muddiest which we call mist and darkness, and other kinds for which we have no name...

Darius was clearly of the opinion
That the air is also man’s dominion,
And that, with paddle or fin or pinion,
We soon or late
Shall navigate
The azure, as now we sail the sea.