The commentary doubles as a synopsis and has therefore been reproduced in full:

This winter started with the worst fog for eight years. Colliers were unable to unload their coal. Transport was disorganised. At the beginning of the year, we expected emergencies. Preparations were made for winter coal stocks.

But coal is not yet used economically. Every year, the fires of Britain send up two and a half million tons of smoke, equal to the waste of ten million tons of coal. This smoke poisons the atmosphere. It blackens buildings and corrodes stonework.

What can be done about it? In industry, devices like this trap the smoke particles instead of letting them loose in the atmosphere. In the home, special stoves save coal as well as preventing smoke.

Economic use of coal would not stop fog, but it would lessen its effect, and solving the problem of smoke would ease the burden on our coal supply.

In the meantime, although there's so much waste, our stocks should see us through this winter.