"Tedstriker" wrote

A dirigble can produce some lift due to it's size, the air would
have so far to travel to get to the top to neutralize the low pressure
up there.

Incorrect. The reason the dirigble has noticible lift is not how far the
air has to travel, but has to do with pure size, (area) and also the
Reynolds Number effect. Larger would measure more lift per square foot than
the smaller per square foot due to the multiplier of the Reynolds Number in
the equation.

But on 13" diameter cylinder, any lift produced would be so
insignificant, as to be barely measurable.

True, it would be barely measurable, but it would be measurable, *if* you
wanted to do it.
--
Jim in NC