The commentary doubles as a synopsis, and is reproduced here in full:

At an open cast site at Newman Spinney, Derbyshire, scientists are experimenting in the underground gasification of coal. Last November, they started boring. The idea is to set fire to the seam underground and draw off gas through bore holes.

Here's the coal seam. Air is pumped down this hole, and the gas forced up this one. To connect the two vertical holes through the seam, they had to drill horizontally from where the coal outcrops and plug up the opening. The experiment may show whether commercially valuable gas can be produced underground without mining.

After months of work, the first experiment is ready. The pipes are in place and the instruments are waiting to measure the gas produced. Men on the site prepare the incendiary bomb, which is to be fired underground. Into this muddy waste come the officials and the press reporters. Alfred Robens is to fire the incendiary bomb. A test bomb shows everyone what should happen underground, and then the real one is set off. Something seems to be happening underground.

USA, Belgium and Russia have been conducting full-scale experiments on underground gasification. Reporters are given all the facts. Then they make a tour of the site. This is only the first of a series of small-scale tests here. As the visitors leave, work goes on to prepare the next experiments.