[Ag-eq] Hay balers

[Jewel]

How do they work?  I looked it up on WikiHow, but learned nothing.
When I had my sight, eons ago, I think that I may have seen one at work.
What I imagine happens is that the baler collects up the dried grass into a hopper, and then a 
mechanical hand picks up a clump of grass from the hopper, drops it into a box the size of a 
bale,and that grass is compressed, and then another and another and another clump is compressed 
until the box is full at which point, somehow or
other, the twine is tied around the bale, the bottom of the box opens and the completed bale drops 
onto a conveyor belt which then dumps it  on the ground ready to be stacked.
How does that sound?  Is it anything like what, actually, happens?

           Jewel