The new 2-level marble shelf

 

After I made my first hanging marble shelf, I still had two pieces of wood left over and everything else I needed to make more.

For some reason, the idea of making a 2-level shelf with all this became an obsession. 

So I did it.

The new build had three innovations:

1. I added clear skinny lightbulbs to the wider jars to increase light flow through the marbles.
2. I attached the jar lids with two screws so they wouldn't rotate when I attached the jar.
3. I did not move the shelf with jars of marbles attached. Thus avoiding having a jar full of marbles falling off and smashing on the tile floor.

I've updated my Instructable to show both designs and the new methods.