I remember these boilers they were quiet big,you connected them to the gas outlet, a bit like you would plug a bulb in,at the bottom there was a gas ring that you would light, and it would boil the washing,then you would get the washing out, rinse in the sink, and through the mangle, they had a little tap at the bottom on the front, to empty them, you would do your whites first, then your coloured and by the time you got to darks, i think the water was probably too dirty to wash with, we thought we were posh when we got one of these, easier than boiling all those pots to do the washing, *such fun*