Meditating with a pyramid on my head is no trouble! Building 20,000 copper cells to power a garden camera on the other hand is big trouble ;)

Did I use wood glue? No. Les Brown didn't mention it so I tried to avoid it. My feeling too is that the simpler we make it (number of materials involved) the more effective it will be.

I did actually use a glue gun on my first pyramid (because it dries instantly and works well for a person in a hurry) which has been in the garden for the last few weeks in the snow and I noticed yesterday that it was falling apart! This is fine. The dimensions were not accurate enough for my taste. Will re-build it when the moment is right :)