James Watt sought to improve Thomas Newcomen's earlier engine. He devised the greatest single improvement ever made to the steam engine.

Newcomen's atmospheric engine required vast amounts of coal to burn as fuel. It was very expensive to use in an area that did not have plentiful coal supplies.

Newcomen's atmospheric engine used steam condensed in a cylinder to create a vacuum beneath a piston, which was driven downwards by atmospheric pressure.

Why was Newcomen's engine so inefficient?