Eric Despite it shrinking down to a more dinky size in recent years, carrying an inhaler is still a real chore. Is it possible to store compressed gas in a more pocket friendly way or has it got to be cylindrical?

Mark Dain I think so else I'd expect to see more box shapes for storing gas (maximizes the available space). Perhaps someone better than physics can explain but my theory would be the shape allows you to store gas at very high pressures without breaking the container. Boxes are weaker due to the edges they have, whereas a cylinder doesn't really have an edge. Like with aerosols I think the pressure has to be higher in the can so spraying works properly. Which is maybe why nobody stores gas in a box; higher pressure makes up for the lost space stacking cylinders.