In case of emergency that can cause a fire, oil from the transformer goes to a separate green pipe shown in picture 11 and the transformer is filled with nitrogen.

But engineers are hoping that their pretesting—using compressed air to fire a ping-pong ball down the pipe, Gillies says—will prevent such a mishap.

You could see him approach the stove, in which there was never any fire, and whose pipe, you know, was of mastic and yellow clay.