"Roderick Stewart" wrote in
message .myzen.co.uk...
In article , Java Jive
wrote:
A favourite trick was to get an old-fashioned tin with a replacable
lid, like a syrup or treacle tin, and punch one hole with a nail
through each of the base and the lid. You then:
1) Remove the lid
2) Seal the hole in the base of the tin with a finger
3) Turn it upside down
4) Fill it with gas from the cooker (gas is lighter than air, so it
goes up into the tin). Er, turn the gas off once you smell gas! That
means it's full!

You couldn't do that now. Modern domestic gas is heavier than air. It
used to be possible to fill a huge plastic bag with the stuff and send
it floating off into the sky, but it's no fun any more.

Natural gas isn't heavier than air. CH4 = 16 or so, compared to air at about
29, so slightly under half the density. (g/mol, 1 mol = constant volume).

LPG - propane at 44 and butane at 58 are heavier, hence problems in boats
with them.

The tin thing still works.