We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Jules
saying something like:

One day I might read the manual to see exactly how it all works ;-)
There's two pipes, so I assume forcing water down to the well base somehow
pressurises things and forces more water up the main bore to the top, so
some such voodoo.

I had one like that and they're still common enough around here. Iirc,
it's a venturi effect down in the footvalve assembly, that draws more
water up than goes down. The only drawback is the need to keep the
sealing in tiptop order which means dragging up the footvalve every so
often and maintaining /repairing /replacing it, else the head of water
in the pressure tank up top is lost, necessitating priming every time
you want it to work.