It's a gas...

As far as I know this gasometer or gas holder as they are now supposed to be called is still in working order. But maybe not for much longer.

Transco have plans to dismantle them all eventually, apart from those that shall remain as a listed building. I confess I do not know what the fate of this one is.

First built around the 1890's, gas holders are now no longer required. So if you see one near you, it might not be around much longer.

: (