From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Compressed propane as target. Also, interesting anecdote.
Date: 21 Feb 1996 18:20:03 GMT

In article <4gep3s$5oe@cloner2.ix.netcom.com>, silent1@ix.netcom.com (The
Silent Observer) says:

>Well, given that I confused the two (>again!<), it'd be >butane< that is 
>decidedly heavier than air; C3H8 is so close to the density of air that 
>it wouldn't stratify at all under any reasonable conditions.  Ordinary 
>thermal activity in dead still air at room temperature would keep it 
>mixed for many weeks...

With a density half again that of air, propane, like CO2 - it's
approximat MW equivalent- stratisfies quite easily. However, once
it is mixed with air it will stay mixed forever, as will gasoline
fumes and the like. Molecular agitation at ordinary temperatures
is more than enough to offset gravity, even for very heavy molecules

Jerry