LB's or KG's it doesn't really matter to me either way ..when i'm back in the UK or here in Spain ...most of the time i'm blanking or too small to weigh
out of curiosity what would you weigh fresh air in ?

In reply to Post #17
Anything with mass has weight, if a suitable vestle is used and air is pumped in and submerged in water, then released a means of measurement can be used to weigh the air