Watt had not yet perfected his steam-engine; but there was a considerable demand for pumping-engines of Newcomen's construction, many of which were made at the Coalbrookdale Works.

The increasing demand for iron gave an impetus to coal-mining, which in its turn stimulated inventors in their improvement of the power of the steam-engine; for the coal could not be worked quickly and advantageously unless the pits could be kept clear of water.

Thus one invention stimulates another; and when the steam-engine had been perfected by Watt, and enabled powerful-blowing apparatus to be worked by its agency, we shall find that the production of iron by means of pit-coal being rendered cheap and expeditious, soon became enormously increased.
We are informed that it was while Richard Reynolds had charge of the Coalbrookdale works that a further important improvement was effected in the manufacture of iron by pit-coal.

Up to this time the conversion of crude or cast iron into malleable or bar iron had been effected entirely by means of charcoal.

The process was carried on in a fire called a finery, somewhat like that of a smith's forge; the iron being exposed to the blast of powerful bellows, and in constant contact with the fuel.