"Morgans" wrote in message
...

"Richard Lamb" wrote

Then it turned around and floated back into the living room - and
rose back up to near 3 feet again!

While I understand the principles involved (temperature/pressure), I've
never seen such a clear demonstration of them.

Fascinating....

As kids, my brother and I would get a helium balloon, and make a gondola
out
of a cut down paper cup. We would then add and subtract ballast, in the
form of tiny torn-up scraps of paper, to fine tune the hover. We could
get
it to hover at about 5 feet, and it would follow the air currents around
the
house. Tons (and hours) of fun!
--
Jim in NC

I was manning a booth at a trade show when a competitor launched a few
hundred He balloons with his company logo on them. He had weighed them off
to neutral bouancy before release so they would wander the hall at constant
altitude - hopefully eye level .

Unfortunately, most of them wound up blocking air return grates overheating
the event center's AC system. I understand that was an expensive show for
the vendor.

Bill Daniels