Interesting, was he able to get the card table out without destroying the fort? What I'd be concerned about there is that with a table-flat ceiling, you are not getting the structural integrity of an arch, but instead have a bunch of dead-weight snow hanging from the outer layer of snow that is probably holding the whole thing up. It can be sculpted into an arch after the fort is built, though.A weather balloon can be a fun and interesting physics toy for kids (and adults!), because it's very squishy yet supports a lot of weight, and is huge but nearly weightless - the balloon I used weighs 7oz. It can be bounced around and floats in the air even better than a beach ball.
To my knowledge, it's never been done this way before! Added Endnotes step explaining the thought process that led to it.
The Quick QuinzeeView Instructable »
Love this idea! Have you tried putting the trail mix on the sheet after it dries, then dribbling another layer of agar on top, for a sort of blister-packed-granola-bar result? Would the challenge be achieving a thin but consistent top coat?