From: utzoo!decvax!harpo!eagle!mhtsa!alice!rhm
Newsgroups: net.physics
Title: Re: Tea Bags
Article-I.D.: alice.1317
Posted: Sun Dec 19 12:02:52 1982
Received: Mon Dec 20 01:30:24 1982
References: avsdS.257

The original estimate of thermal expansion of air was correct.
At room temperature (300K) it amounts to 1/300 per degree Celsius.

Since the pressure does not increase by any measurable amount, the
expansion available is limited to a factor of about 370/300, which
is inadequate to explain the effect.

I think the tea bag question is still open.