An apparatus for holding and measuring of gas; in gas works, a huge iron cylinder closed at one end and having the other end immersed in water, in which it is made to rise or fall, according to the volume of gas it contains, or the pressure required.

An enormous above ground tank, contained in a network of steel struts and ladders. (You can see similar tanks at any oil refinery.) The tank got lower and lower as the gas was used up and rose again when it was refilled. They were prime targets for enemy planes - a few bullets could send the whole lot up in flames in seconds. No-one wanted to live near a gasometer but they had to be close to the homes they supplied.

a large gas-tight spherical or cylindrical tank for holding gas to be used as fuel

a meter for measuring the amount of gas flowing through a particular pipe